weight loss

Best way to lose weight

There is no one best way to lose weight, which is why doctors and dietitians work to understand your personal circumstances when making recommendations. There is no quick fix. Improving your diet and increasing activity can be key to losing weight, although are not the only factors that need to be considered. When aiming to lose weight it is important to have realistic goals that are achievable. Success boosts confidence in your ability to lose weight. A weight loss of between 0.5 to 2 pounds (0.5-1kg) a week is a safe and realistic target. Experts recommend losing 5 to 10 percent of your body weight within the first 6 months of treatment 1). If you weigh 200 pounds, this means losing as little as 10 pounds. Moreover, it’s not just about your weight on the scales, losing inches from your waist helps to lower your risk of conditions like type 2 diabetes and high blood pressure. To reach and stay at a healthy weight over the long term, you must focus on your overall health and lifestyle habits, not just on what you eat. Successful weight-loss programs should promote healthy behaviors that help you lose weight safely, that you can stick with every day, and that help you keep the weight off. People who successfully lose weight and keep it off develop techniques to make their new lifestyle and activity habits an enjoyable way of life and also make them life long.

Most American adults are overweight or obese. Doctors and dietitians assess weight by measuring your Body Mass Index (BMI), a ratio of weight to height. The BMI is defined as the body mass in kilogram (Kg) that is divided by the square of the body height in meter (m2), and is expressed in units of kg/m², resulting from mass in kilograms and height in meters (see Figure 1). You can also use an online BMI calculator (https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm). A BMI between 25 and 29.9 kg/m² is considered overweight, and obesity is a BMI of 30 kg/m² or higher. Waist to hip ratio should also be measured, in men more than 1:1 and women more than 0:8 is considered significant (see Figure 3). Being overweight or obese puts you at risk for a myriad of health problems, such as ischemic heart disease, high blood pressure, cardiovascular disease, fatty liver disease, breathing problems (obstructive sleep apnea, ventilatory failure and asthma), type 2 diabetes, gastro-esophageal reflux disease (GERD), gallstones, some cancers, Alzheimer’s disease, renal failure and other health problems 2). Ninety per cent of people with type 2 diabetes have a body mass index (BMI) greater than 23 kg/m² and conversely it is estimated that the attributable risk of obesity for diabetes is between 30% and 70% 3).

Many factors can contribute to your weight. These factors include your environment (cultural and societal), family history and genetics, metabolism (the way your body changes food and oxygen into energy), and behavior or habits. Other causes of obesity include reduced physical activity, insomnia, food habits, endocrine disorders, medications, food advertisements, and energy metabolism 4). Most common syndromes associated with obesity include Prader Willi syndrome and MC4R syndromes, others like fragile X, Bardet-Beidl syndrome, Wilson Turner congenital leptin deficiency, and Alstrom syndrome are also associated with obesity 5).

You weight loss programs and weight loss maintenance programs should focus on changing your behavior to reduce energy intake by cutting unhealthy foods, decreasing sugar‐sweetened beverage consumption and fat intake, portion control, increasing fruit and vegetable intake, and adhering to a diet 6). Additionally, energy expenditure should be promoted through increasing physical activity.

Obesity is the result of an energy imbalance between your daily energy intake and your energy expenditure resulting in excessive weight gain 7). The amount of energy or calories you get from food and drinks (energy IN) is balanced with the energy your body uses for things like breathing, digesting, and being physically active (energy OUT):

  • The same amount of energy IN and energy OUT over time = weight stays the same (Energy Balance)
  • More energy IN than OUT over time = Weight Gain
  • More energy OUT than IN over time = Weight Loss

In order to lose weight, energy expenditures must exceed energy intake. To lose weight, most people need to reduce the number of calories they get from food and beverages (energy IN) and increase their physical activity (energy OUT). To achieve this imbalance, you can decrease energy intake, increase energy expenditures or combine a decrease in intake with an increase in expenditures. Being physically active and eating fewer calories will help you lose weight and keep the weight off over time. As a result, most weight loss recommendations advise combining a low caloric diet with an exercise program in order to achieve a significant energy deficit 8). A long-standing consistent observation is that regular exercise by itself is prescribed in small to moderate amounts resulting in modest weight loss or in some cases weight gain 9).

For a weight loss of 1–1 ½ pounds per week, daily intake should be reduced by 500 to 750 calories. In general 10):

  • Eating plans that contain 1,200–1,500 calories each day will help most women lose weight safely.
  • Eating plans that contain 1,500–1,800 calories each day are suitable for men and for women who weigh more or who exercise regularly.

Very low calorie diets of fewer than 800 calories per day should not be used unless you are being monitored by your doctor.

Energy balance is also important for maintaining a healthy weight. To maintain a healthy weight, your energy IN and OUT don’t have to balance exactly every day. It’s the balance over time that helps you maintain a healthy weight.

You can reach and maintain a healthy weight if you:

  • Follow a healthy diet, and if you are overweight or obese, reduce your daily intake by 500 calories for weight loss
  • Are physically active
  • Limit the time you spend being physically inactive

While people vary quite a bit in the amount of physical activity (exercise) they need for weight control, many can maintain their weight by doing 150 to 300 minutes (2 ½ to 5 hours) a week of moderate-intensity activity such as brisk walking. People who want to lose a large amount of weight (more than 5 percent of their body weight) and people who want to keep off the weight that they’ve lost may need to be physically active for more than 300 minutes of moderate-intensity activity each week.

American College of Sports Medicine recommendations for physical activity for Weight Loss and Prevention of Weight Regain for Adults 11):

  • Maintain and improving health: 150 minutes/week
  • Prevention of weight gain: 150 – 250 minutes/week
  • Promote clinically significant weight loss: 225 – 420 minutes/week
  • Prevention of weight gain after weight loss: 200 – 300 minutes/week

Strong evidence exists that exercise (physical activity) can reduce weight gain in those at risk for obesity, and many exercise training programs are capable of producing at least modest weight loss (~2 kg) 12). A question often encountered in the clinical setting from patients is how much exercise is needed to lose weight and what type of exercise training should be performed. Overall, the changes in weight in response to exercise training without caloric restriction are highly heterogeneous and individual differences can span weight gain to clinically significant weight loss 13). Patients should should consult their clinicians or dietitians on what are reasonable expectations based on their specific weight loss program. However, research data suggest that physical activity has an important role in the amount of weight regain following successful weight loss 14). Therefore, patients attempting to reduce recidivism after weight loss should engage in physical activity levels above 200 minutes/week 15).

Furthermore, high levels of physical activity and cardiorespiratory fitness (fitness) are inversely associated with cardiovascular disease, type 2 diabetes and all-cause mortality 16). Several epidemiological studies even suggest that high levels of physical activity or cardiorespiratory fitness reduces the health risk of obesity 17), 18). Moreover, cardiorespiratory fitness levels have been shown to alter the relationship of the obesity paradox, where high cardiorespiratory fitness level is associated with greater survival in all body mass index (BMI) categories 19). In summary, patients are encourage to adhere to exercise programs or engage in regular physical activity regardless of the weight loss achieved.

Another question that is often encountered in the clinical setting is if there is a difference between weight loss achieved through dietary means or through exercise training in terms of cardiovascular and type 2 diabetes mellitus risk factors. In an elegantly designed study, Ross et al. 20) randomized obese men (n= 52) to diet-induced weight loss, exercise induced weight loss, exercise without weight loss, or a control group for 3 months. The diet-induced and exercise-induced weight loss groups lost approximately 7 kg of weight (8% weight reduction), and had significant reductions in total fat mass, visceral fat and increased glucose disposal 21). However, the exercise-induced weight loss group had a greater reduction in total fat mass compared to the diet induced weight loss group 22). Importantly, the exercise-induced weight loss improved cardiorespiratory fitness (fitness) whereas the dietary group did not. In the group who performed exercise training without weight loss, the participants still experienced reductions in visceral fat and increased cardiorespiratory fitness.

The observations by Ross et al. 23) reaffirm that an exercise training program still confers health benefits to obese patients even in the absence of weight loss. Although dieting without exercise training has potential cardiovascular benefits, exercise training should be encouraged by to help patients improve cardiorespiratory fitness levels, which is an independent risk factor for cardiovascular diseases, type 2 diabetes mellitus and mortality 10, and may further augment the negative energy balance created by caloric restriction. Lastly, Ross’ observations suggest that there is a rationale for exercise training to be a part of weight loss programs as the authors observed greater changes in visceral fat, oral glucose tolerance, and glucose disposal in the exercise training group with clinically significant weight loss compared to the group with exercise without weight loss group 24).

Figure 1. Body Mass Index calculator

Body Mass Index calculator

Table 1. Body Mass Index range

BMI Range (kg/m²)
Weight class
Less than 16.5 kg/m²Severely Underweight
16.5 – 18.5 kg/m²Underweight
18.5 – 25 kg/m²
Normal
25 – 30 kg/m²Overweight
30 – 34.9 kg/m²Obese, Class 1
35 – 39.9 kg/m²Obese, Class 2
More than 40 kg/m²Obese, Class 3 (Morbidly Obese)

Figure 2. Body Mass Index graph

BMI graph

Footnote: A graph of body mass index (BMI) as a function of body mass and body height. The dashed lines represent subdivisions within a major class. The Body mass index scale show all people with high level of muscles also overweight or obese. This is because the BMI scale is designed in accordance to the body fat levels not body muscles mass levels. Therefore, BMI measure is not an accurate measure for muscular individual.

Figure 3. Waist to hip ratio
Waist to hip ratio measurement

Behaviors that will help you lose weight and keep it off

Set the Right Goals

Setting the right goals is an important first step. Most people trying to lose weight focus on just that one goal: weight loss. However, the most productive areas to focus on are the dietary and physical activity changes that will lead to long-term weight change. Successful weight managers are those who select two or three goals at a time that are manageable.

Useful goals should be:

  1. Specific;
  2. Attainable (doable); and
  3. Forgiving (less than perfect).

For example, “exercise more” is a great goal, but it’s not specific. “Walk 5 miles every day” is specific and measurable, but is it doable if you’re just starting out? “Walk 30 minutes every day” is more attainable, but what happens if you’re held up at work one day and there’s a thunderstorm during your walking time another day? “Walk 30 minutes, 5 days each week” is specific, doable, and forgiving. In short, a great goal!

Be prepared for setbacks

Setbacks are normal. After a setback, like overeating at a family or workplace gathering, try to regroup and focus on getting back to your healthy eating plan as soon as you can. Try to eat only when you’re sitting at your dining room or kitchen table. At work, avoid areas where treats may be available. Track your progress using online food or physical activity trackers, such as the Body Weight Planner (https://www.niddk.nih.gov/bwp), that can help you keep track of the foods you eat, your physical activity, and your weight. The Body Weight Planner allows users to make personalized calorie and physical activity plans to reach a goal weight within a specific time period and to maintain it afterwards. These tools may help you stick with it and stay motivated.

Overcome roadblocks

Remind yourself why you want to be healthier. Perhaps you want the energy to play with your nieces and nephews or to be able to carry your own grocery bags. Recall your reasons for making changes when slip-ups occur. Decide to take the first step to get back on track.

Problem-solve to “outsmart” roadblocks. For example, plan to walk indoors, such as at a mall, on days when bad weather keeps you from walking outside.

Ask a friend or family member for help when you need it, and always try to plan ahead. For example, if you know that you will not have time to be physically active after work, go walking with a coworker at lunch or start your day with an exercise video.

Nothing Succeeds Like Success

Shaping is a behavioral technique in which you select a series of short-term goals that get closer and closer to the ultimate goal (e.g., an initial reduction of fat intake from 40 percent of calories to 35 percent of calories, and later to 30 percent). It is based on the concept that “nothing succeeds like success.”

Shaping uses two important behavioral principles:

  1. Consecutive goals that move you ahead in small steps are the best way to reach a distant point; and
  2. Consecutive rewards keep the overall effort invigorated.

Reward Success (But Not With Food)

An effective reward is something that is desirable, timely, and dependent on meeting your goal. The rewards you choose may be material (e.g., a movie or music CD, or a payment toward buying a more costly item) or an act of self-kindness (e.g., an afternoon off from work or just an hour of quiet time away from family). Frequent small rewards, earned for meeting smaller goals, are more effective than bigger rewards that require a long, difficult effort.

Balance Your Food Checkbook

“Self-monitoring” refers to observing and recording some aspect of your behavior, such as calorie intake, servings of fruits and vegetables, amount of physical activity, etc., or an outcome of these behaviors, such as weight. Self-monitoring of a behavior can be used at times when you’re not sure how you’re doing, and at times when you want the behavior to improve. Self-monitoring of a behavior usually moves you closer to the desired direction and can produce “real-time” records for review by you and your health care provider. For example, keeping a record of your physical activity can let you and your provider know quickly how you’re doing. When the record shows that your activity is increasing, you’ll be encouraged to keep it up. Some patients find that specific self-monitoring forms make it easier, while others prefer to use their own recording system.

While you may or may not wish to weigh yourself frequently while losing weight, regular monitoring of your weight will be essential to help you maintain your lower weight. When keeping a record of your weight, a graph may be more informative than a list of your weights. When weighing yourself and keeping a weight graph or table, however, remember that one day’s diet and exercise patterns won’t have a measurable effect on your weight the next day. Today’s weight is not a true measure of how well you followed your program yesterday, because your body’s water weight will change from day to day, and water changes are often the result of things that have nothing to do with your weight-management efforts.

Avoid a Chain Reaction

Stimulus (cue) control involves learning what social or environmental cues seem to encourage undesired eating, and then changing those cues. For example, you may learn from reflection or from self-monitoring records that you’re more likely to overeat while watching television, or whenever treats are on display by the office coffee pot, or when around a certain friend. You might then try to change the situation, such as by separating the association of eating from the cue (don’t eat while watching television), avoiding or eliminating the cue (leave the coffee room immediately after pouring coffee), or changing the circumstances surrounding the cue (plan to meet your friend in a nonfood setting). In general, visible and reachable food items are often cues for unplanned eating.

Get the Fullness Message

Changing the way you go about eating can make it easier to eat less without feeling deprived. It takes 15 or more minutes for your brain to get the message that you’ve been fed. Eating slowly will help you feel satisfied. Eating lots of vegetables and fruits can make you feel fuller. Another trick is to use smaller plates so that moderate portions do not appear too small. Changing your eating schedule, or setting one, can be helpful, especially if you tend to skip, or delay, meals and overeat later.

Seek support

Ask for help or encouragement from your family, friends, or health care professionals. You can get support in person, through email or texting, or by talking on the phone. You can also join a support group. Specially trained health professionals can help you change your lifestyle.

Weight-loss programs to avoid

A fad weight loss diet is any diet that promises fast weight loss without a scientific basis. These diets often eliminate entire food groups and as a result do not provide a wide range of important nutrients. Fad diets may provide short-term results but they are difficult to sustain and can cause serious health problems. The best approach to weight loss is to follow a long-term, healthy and balanced eating plan and to exercise regularly.

Avoid weight-loss programs that make any of the following promises:

  • Lose weight without diet or exercise!
  • Lose weight while eating as much as you want of all your favorite foods!
  • Lose 30 pounds in 30 days!
  • Lose weight in specific problem areas of your body!

Other warning signs to look out for include:

  • very small print, asterisks, and footnotes, which may make it easy to miss important information
  • before-and-after photos that seem too good to be true
  • personal endorsements that may be made up

You can report false claims or scams by weight-loss programs to the Federal Trade Commission (https://www.ftc.gov).

Fad diets often lead to fast weight loss at first. But most of this weight loss is water and lean muscle, rather than fat. When you eat very little, your body begins to break down muscle to meet energy (kilojoule) needs. Unfortunately, this occurs much more easily than the breakdown of fat stores.

Breaking down muscle leads to:

  • Water loss, making it seem like you’re losing weight quickly
  • A reduced metabolic rate, so when the diet is stopped, it is much easier for your body to gain fat than it was prior to going on the diet.

As a result, over time, people can diet themselves fatter.

Fad diets often encourage a short-term change in eating behavior, rather than encouraging long-term, sustainable changes. It is essential that any diet meets nutritional needs, is practical and suitable for individual lifestyles.

Regular physical activity is important for those wanting to lose weight to help maintain muscle mass.

What if I need more help losing weight?

If a weight-loss program is not enough to help you reach a healthy weight, ask your health care professional about other types of weight-loss treatments. Prescription medicines to treat overweight and obesity, combined with healthy lifestyle changes, may help some people reach a healthy weight. For some people who have extreme obesity, bariatric surgery may be an option.

Who might benefit from weight-loss medications?

Weight-loss medications are meant to help people who may have health problems related to overweight or obesity. Before prescribing a weight-loss medication, your doctor also will consider:

  • the likely benefits of weight loss
  • the medication’s possible side effects
  • your current health issues and other medications
  • your family’s medical history
  • cost

Health care professionals often use BMI to help decide who might benefit from weight-loss medications. Your doctor may prescribe a medication to treat your overweight or obesity if you are an adult with:

  • a BMI of 30 or more or
  • a BMI of 27 or more and you have weight-related health problems, such as high blood pressure or type 2 diabetes.

Weight-loss medications aren’t for everyone with a high BMI. Some people who are overweight or obese may lose weight with a lifestyle program that helps them change their behaviors and improve their eating and physical activity habits. A lifestyle program may also address other factors that affect weight gain, such as eating triggers and not getting enough sleep.

The U.S. Food and Drug Administration (FDA) has approved most weight-loss medications only for adults. The prescription medication orlistat (Xenical) is FDA-approved for children ages 12 and older.

The table below lists FDA-approved prescription medications for weight loss. The FDA has approved five of these drugs—orlistat (Xenical, Alli), lorcaserin (Belviq), phentermine-topiramate (Qsymia), naltrexone-bupropion (Contrave), and liraglutide (Saxenda)—for long-term use. You can keep taking these drugs as long as you are benefiting from treatment and not having unpleasant side-effects.

Some weight-loss medications that curb appetite are approved by the FDA only for short-term use, or up to 12 weeks. Although some doctors prescribe them for longer periods of time, not many research studies have looked at how safe and effective they are for long-term use.

Pregnant women should never take weight-loss medications. Women who are planning to get pregnant also should avoid these medications, as some of them may harm a fetus.

Table 2. Prescription medications approved for Overweight and Obesity treatment

Weight-loss medicationApproved forHow it worksCommon side effectsWarnings
Orlistat (Xenical)

Available in lower dose without prescription (Alli)

Adults and children ages 12 and olderWorks in your gut to reduce the amount of fat your body absorbs from the food you eatdiarrhea
gas
leakage of oily stools
stomach pain
Rare cases of severe liver injury have been reported. Avoid taking with cyclosporine. Take a multivitamin pill daily to make sure you get enough of certain vitamins that your body may not absorb from the food you eat.
Lorcaserin (Belviq)

WITHDRAWN FROM MARKET in February 2020

AdultsActs on the serotonin receptors in your brain. May help you feel full after eating smaller amounts of food.constipation
cough
dizziness
dry mouth
feeling tired
headaches
nausea
Lorcaserin (Belviq) was voluntarily withdrawn from the U.S. market in February 2020 at the request of the FDA because a clinical trial showed an increased occurrence of cancers.

The FDA recommends that patients should stop taking lorcaserin and talk to their health care professionals about alternative weight-loss medicines and weight management programs.

Phentermine-topiramate (Qsymia)AdultsA mix of two medications: phentermine, which lessens your appetite, and topiramate, which is used to treat seizures or migraine headaches. May make you less hungry or feel full sooner.constipation
dizziness
dry mouth
taste changes, especially with carbonated beverages
tingling of your hands and feet
trouble sleeping
Don’t use if you have glaucoma or hyperthyroidism. Tell your doctor if you have had a heart attack or stroke, abnormal heart rhythm, kidney disease, or mood problems.

MAY LEAD TO BIRTH DEFECTS. DO NOT TAKE QSYMIA IF YOU ARE PREGNANT OR PLANNING A PREGNANCY. Do not take if you are breastfeeding.

Naltrexone-bupropion (Contrave)AdultsA mix of two medications: naltrexone, which is used to treat alcohol and drug dependence, and bupropion, which is used to treat depression or help people quit smoking. May make you feel less hungry or full sooner.constipation
diarrhea
dizziness
dry mouth
headache
increased blood pressure
increased heart rate
insomnia
liver damage
nausea
vomiting
Do not use if you have uncontrolled high blood pressure, seizures or a history of anorexia or bulimia nervosa. Do not use if you are dependent on opioid pain medications or withdrawing from drugs or alcohol. Do not use if you are taking bupropion (Wellbutrin, Zyban).

MAY INCREASE SUICIDAL THOUGHTS OR ACTIONS.

Liraglutide (Saxenda)

Available by injection only

AdultsMay make you feel less hungry or full sooner. At a lower dose under a different name, Victoza, FDA-approved to treat type 2 diabetes.nausea
diarrhea
constipation
abdominal pain
headache
raised pulse
May increase the chance of developing pancreatitis. Has been found to cause a rare type of thyroid tumor in animals.
Other medications that curb your desire to eat include:

  • Phentermine
  • Benzphetamine
  • Diethylpropion
  • Phendimetrazine
AdultsIncrease chemicals in your brain to make you feel you are not hungry or that you are full.

Note: FDA-approved only for short-term use—up to 12 weeks

dry mouth
constipation
difficulty sleeping
dizziness
feeling nervous
feeling restless
headache
raised blood pressure
raised pulse
Do not use if you have heart disease, uncontrolled high blood pressure, hyperthyroidism, or glaucoma. Tell your doctor if you have severe anxiety or other mental health problems.

What are the benefits of using prescription medications to lose weight?

When combined with changes to behavior, including eating and physical activity habits, prescription medications may help some people lose weight. On average, people who take prescription medications as part of a lifestyle program lose between 3 and 9 percent more of their starting body weight than people in a lifestyle program who do not take medication. Research shows that some people taking prescription weight-loss medications lose 10 percent or more of their starting weight. Results vary by medication and by person.

Weight loss of 5 to 10 percent of your starting body weight may help improve your health by lowering blood sugar, blood pressure, and triglycerides. Losing weight also can improve some other health problems related to overweight and obesity, such as joint pain or sleep apnea. Most weight loss takes place within the first 6 months of starting the medication.

What are the concerns with using prescription medications to lose weight?

Experts are concerned that, in some cases, the side effects of prescription medications to treat overweight and obesity may outweigh the benefits. For this reason, you should never take a weight-loss medication only to improve the way you look. In the past, some weight-loss medications were linked to serious health problems. For example, the FDA recalled fenfluramine and dexfenfluramine (part of the “fen-phen” combination) in 1997 because of concerns related to heart valve problems.

Possible side effects vary by medication and how it acts on your body. Most side effects are mild and most often improve if you continue to take the medication. Rarely, serious side effects can occur.

Can medications replace physical activity and healthy eating habits as a way to lose weight?

Medications don’t replace physical activity or healthy eating habits as a way to lose weight. Studies show that weight-loss medications work best when combined with a lifestyle program. Ask your doctor or other health care professional about lifestyle treatment programs for weight management that will work for you.

How long will I need to take weight-loss medication?

How long you will need to take weight-loss medication depends on whether the drug helps you lose and maintain weight and whether you have any side effects. If you have lost enough weight to improve your health and are not having serious side effects, your doctor may advise that you stay on the medication indefinitely. If you do not lose at least 5 percent of your starting weight after 12 weeks on the full dose of your medication, your doctor will probably advise you to stop taking it. He or she may change your treatment plan or consider using a different weight-loss medication. Your doctor also may have you try different lifestyle, physical activity, or eating programs; change your other medications that cause weight gain; or refer you to a bariatric surgeon to see if weight-loss surgery might be an option for you.

Because obesity is a chronic condition, you may need to continue changes to your eating and physical activity habits and other behaviors for years—or even a lifetime—to improve your health and maintain a healthy weight.

Will I regain some weight after I stop taking weight-loss medication?

You will probably regain some weight after you stop taking weight-loss medication. Developing and maintaining healthy eating habits and increasing physical activity may help you regain less weight or keep it off. Federal physical activity guidelines recommend at least 150 minutes a week of moderate-intensity aerobic activity and at least 2 days a week of muscle-strengthening activities. You may need to do more than 300 minutes of moderate-intensity activity a week to reach or maintain your weight-loss goal.

Best diet to lose weight

If people are overweight, it’s usually because they eat and drink more calories than they need. To lose weight, it’s important you make lifestyle changes that focus on reducing your calories from food and beverages, a healthy eating plan, and portion control. Over time, these changes will become part of your everyday routine. A healthy eating plan gives your body the nutrients it needs every day while staying within your daily calorie goal for weight loss. A healthy eating plan also will lower your risk for heart disease and other health conditions. However, the healthy eating plan is not suitable for children and young people or pregnant women.

A healthy eating plan:

  • Emphasizes vegetables, fruits, whole grains, and fat-free or low-fat dairy products
  • Includes lean meats, poultry, fish, beans, eggs, and nuts
  • Limits saturated and trans fats, sodium, and added sugars
  • Controls portion sizes

To lose weight, most people need to reduce the number of calories they get from food and beverages (energy IN) and increase their physical activity (energy OUT). Your doctor may recommend a lower-calorie diet such as 1,200 to 1,500 calories a day for women and 1,500 to 1,800 calories a day for men. The calorie level depends on your body weight and physical activity level. A lower calorie diet with a variety of healthy foods will give you the nutrients you need to stay healthy.

Start by determining how many calories you should consume each day. To do so, you need to know how many calories you need to maintain your current weight. Doing this requires a few simple calculations. First, multiply your current weight by 15 — that’s roughly the number of calories per pound of body weight needed to maintain your current weight if you are moderately active. Moderately active means getting at least 30 minutes of physical activity a day in the form of exercise (walking at a brisk pace, climbing stairs, or active gardening). Let’s say you’re a woman who is 5 feet, 4 inches tall and weighs 155 pounds, and you need to lose about 15 pounds to put you in a healthy weight range. If you multiply 155 by 15, you will get 2,325, which is the number of calories per day that you need in order to maintain your current weight (weight-maintenance calories). To lose weight, you will need to get below that total.

For example, to lose 1 to 2 pounds a week — a rate that experts consider safe — your food consumption should provide 500 to 1,000 calories less than your total weight-maintenance calories. If you need 2,325 calories a day to maintain your current weight, reduce your daily calories to between 1,325 and 1,825. If you are sedentary, you will also need to build more activity into your day. In order to lose at least a pound a week, try to do at least 30 minutes of physical activity on most days, and reduce your daily calorie intake by at least 500 calories. However, calorie intake should not fall below 1,200 a day in women or 1,500 a day in men, except under the supervision of a health professional. Eating too few calories can endanger your health by depriving you of needed nutrients.

For a weight loss of 1–1 ½ pounds per week, daily intake should be reduced by 500 to 750 calories. In general:

  • Eating plans that contain 1,200–1,500 calories each day will help most women lose weight safely.
  • Eating plans that contain 1,500–1,800 calories each day are suitable for men and for women who weigh more or who exercise regularly.

Very low calorie diets of fewer than 800 calories per day should not be used unless you are being monitored by your doctor.

1200 Calories eating plan

Over the next 12 weeks you’re going to make healthier choices to help you lose weight and keep it off. From today, you’ll stick to a daily calorie intake of 1200 Calories.

Table 3. 1200 Calories Traditional American Cuisine

BreakfastEnergy (Kcal)Fat (gram)% FatExchange for:
Whole-wheat bread, 1 med. slice701.215(1 Bread/Starch)
Jelly, regular, 2 tsp 3000(½ Fruit)
Cereal, shredded wheat, ½ Cup10414(1 Bread/Starch)
Milk, 1%, 1 Cup102323(1 Milk)
Orange juice, ¾ Cup 7800(1½ Fruit)
Coffee, regular, 1 Cup 500(Free)
Breakfast Total 3895.210
LunchEnergy (Kcal)Fat (gram)% FatExchange for:
Roast beef sandwich
Whole-wheat bread, 2 medium slices1392.415(2 Bread/Starch)
Lean roast beef, unseasoned, 2oz601.523(2 Lean Protein)
Lettuce, 1 leaf100
Tomato, 3 med. slices 1000(1 Vegetable)
Mayonnaise, low-calorie, 1 tsp151.796(1⁄3 Fat)
Apple, 1 medium8000(1 Fruit)
Water000(Free)
Lunch Total 3055.616
DinnerEnergy (Kcal)Fat (gram)% FatExchange for:
Salmon, 2 oz edible 103540(2 Lean Protein)
Vegetable oil, 1½ tsp607100(1½ Fat)
Baked potato, ¾ medium 10000(1 Bread/Starch)
Margarine, 1 tsp344100(1 Fat)
Green beans ½ Cup, seasoned with margarine
5224(1 Vegetable)
(½ Fat)
Carrots, seasoned3520(1 Vegetable)
White dinner roll, 1 small70226(1 Bread/Starch)
Iced tea, unsweetened000(Free)
Water000(Free)
Dinner Total 4542039
SnackEnergy (Kcal)Fat (gram)% FatExchange for:
Popcorn, 2½ Cups 6900(1 Bread/Starch)
Margarine, ¾ tsp303100(¾ Fat)
Grand Total12473424

Footnotes:  Total Calories = 1,247; Total Carb = 58% kcals; Total Fat = 26% kcals; Saturated Fat = 7% kcals; Cholesterol = 96 mg; Protein = 19% kcals; Sodium (salt) = 1,043 mg (No salt added in recipe preparation or as seasoning). Consume at least 32 oz (950 ml) water. Recommended Dietary Allowance (RDA) is average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy people. 100% RDA met for all nutrients except: vitamin E 80%, vitamin B2 96%, vitamin B6 94%, Calcium 68%, Iron 63% and Zinc 73%.

[Source 25) ]

1600 Calories eating plan

Table 4. 1600 Calories Traditional American Cuisine

BreakfastEnergy (Kcal)Fat (gram)% FatExchange for:
Whole-wheat bread, 1 medium slice701.215(1 Bread/Starch)
Jelly, regular, 2 tsp 3000(½ Fruit)
Cereal, shredded wheat, ½ Cup10414(1 Bread/Starch)
Milk, 1%, 1 Cup102323(1 Milk)
Orange juice, ¾ Cup 7800(1½ Fruit)
Coffee, regular, 1 Cup500(Free)
Milk, 1%, 1 oz130.0323(1⁄8 Milk)
Breakfast Total 4025.2312
LunchEnergy (Kcal)Fat (gram)% FatExchange for:
Roast beef sandwich
Whole-wheat bread, 2 medium slices1392.415(2 Bread/Starch)
Lean roast beef, unseasoned, 2 oz601.523(2 Lean Protein)
American cheese, low-fat and low-sodium, 1 slice
(¾ oz)
461.836(1 Lean Protein)
Lettuce, 1 leaf100
Tomato, 3 medium slices 1000(1 Vegetable)
Mayonnaise, low-calorie, 2 tsp303.399(2⁄3 Fat)
Apple, 1 medium8000(1 Fruit)
Water000(Free)
Lunch Total 366922
DinnerEnergy (Kcal)Fat (gram)% FatExchange for:
Salmon, 3 oz edible 155740(3 Lean Protein)
Vegetable oil, 1½ tsp607100(1½ Fat)
Baked potato, ¾ medium10000(1 Bread/Starch)
Margarine, 1 tsp344100(1 Fat)
Green beans ½ Cup, seasoned with margarine5224(1 Vegetable) (½ Fat)
Carrots ½ Cup, seasoned with margarine
5224(1 Vegetable) (½ Fat)
White dinner roll, 1 medium80333(1 Bread/Starch)
Ice milk, ½ Cup92328(½ Fat)
Iced tea, unsweetened, 1 Cup000(Free)
Water000(Free)
Dinner Total 6252840
SnackEnergy (Kcal)Fat (gram)%FatExchange for:
Popcorn, 2½ Cups 6900(1 Bread/Starch)
Margarine, 1½ tsp516100(1½ Fat)
Grand Total14904829

Footnotes:  Total Calories = 1,490; Total Carb = 52% kcals; Total Fat = 29% kcals; Saturated Fat = 8% kcals; Cholesterol = 142 mg; Protein = 19% kcals; Sodium (salt) = 1,341 mg (No salt added in recipe preparation or as seasoning). Consume at least 32 oz (950 ml) water. Recommended Dietary Allowance (RDA) is average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy people. 100% RDA met for all nutrients except: vitamin E 99%, Iron 73% and Zinc 91%.

[Source 26) ]

Intermittent fasting

Intermittent fasting also known as “periodic fasting”, “time‐restricted feeding”, “alternate-day fasting” or “reduced meal frequency”, is when people restrict the time (e.g., 16–48 hours) during the day when they can eat 27), is another way of reducing food intake that is gaining attention as a strategy for weight loss and health benefits. Alternate-day fasting is one type of intermittent fasting that consists of a “fast day” (eating no calories to one-fourth of caloric needs) alternating with a “fed day,” or a day of unrestricted eating. Intermittent fasting focuses on the timing of when you can consume meals either within a day or a week. For example, someone may eat only during a 12-hour time period, such as 7 a.m. to 7 p.m. Skipping meals commonly consists of a daily fast for 16 hours, a 24-hour fast on alternate days, or a fast 2 days per week on non-consecutive days 28). Intermittent fasting is not a diet plan. While it may have some of the same health benefits as a diet, it’s really an eating pattern. It means you fast (don’t eat) during a certain period of time each day (usually an extended period of time). You then eat during another period of time each day (usually a smaller period of time). While you’re fasting, you can drink beverages that don’t contain calories, including water, black coffee, and unsweetened tea. There is still much for scientists and doctors to learn about intermittent fasting. Researchers have conducted only a few studies of intermittent fasting as a strategy for weight loss. They have no long-term data on the safety, how it affects the body and its systems and effectiveness of intermittent fasting for long-term weight maintenance.

Some popular approaches to intermittent fasting include:

  • Alternate-day fasting. Eat a normal diet one day and either completely fast or have one small meal (less than 500 calories) the next day.
  • 5:2 fasting. Eat a normal diet five days a week and fast two days a week.
  • Daily time-restricted fasting. Eat normally but only within an eight-hour window each day. For example, skip breakfast but eat lunch around noon and dinner by 8 p.m.

How fasting and eating is divided each day is called an eating schedule. One of the most common, easy-to-follow schedules is 16:8. This means you fast for a 16-hour period of time and eat your daily meals during an 8-hour period of time. For example, you may want to fast from 7 p.m. until 11 a.m. the next day. You would then eat a healthy lunch and dinner between 11 a.m. and 7 p.m. You wouldn’t eat anything after 7 p.m. until 11 a.m. the next day. This is just an example of times. You can select any 16-hour and 8-hour block of time that works best for your schedule. But it’s important to keep your eating window at the same every day.

Other intermittent fasting schedules include 18:6 (when you fast for 18 hours and eat for 6 hours) or alternating days. With alternating days, you fast for 24 hours, then eat a healthy diet for the next 24 hours, then fast again for the following 24 hours. This schedule continues using the every-other-day format. Another schedule option is 5:2. This is when you fast for two days a week, and eat a normal, healthy diet the other five days. This is a little different, though, as this schedule allows you eat one small meal of 500 to 600 calories on your fasting days.

The time you’re allowed to eat is called your eating window. During your eating window, focus on eating a healthy diet and maintaining portion control. Don’t eat too many calories and avoid junk food and fast food. While you don’t need to eat anything in particular, you do need to make sure you’re getting the nutrition you need. Some people choose to use the Mediterranean diet as a guideline for what to eat. This plan focuses on fruits, vegetables, beans, whole grains, and fish. You can also choose lean proteins and healthy fats.

During fasting, caloric consumption often ranges from zero to 25% of caloric needs 29). Alternative day fasting may consist of 24-hour fasts followed by a 24-hour eating period that can be done several times a week such as a 5:2 strategy when there are 2 fast days mixed into 5 nonrestrictive days 30). For time restricted fast programs, variations include 16-hour fasts with 8 hour feeding times, 20-hour fasts with 4-hour feed times or other similar versions 31). While both caloric restriction and intermittent fasting may result in overall decreased caloric intake, this is not integral to intermittent fasting. Intermittent fasting has been linked to better glucose control in both humans and animals 32). However, long-term adherence to caloric restriction is low while adherence to intermittent fasting may be more promising.

While researchers are still studying intermittent fasting, some research has shown it offers some health benefits. For starters, it’s common to lose weight when following intermittent fasting. That’s because your body is using fat—not glucose—as its energy source. Additionally, if you make wise food choices when you do eat, you’re likely eating fewer calories than before you started intermittent fasting. If you add exercise to the mix, it’s a great combination for not only weight loss, but also improved health benefits. Intermittent fasting may help people who have cardiovascular disease, neurological disorders, and some cancers. Intermittent fasting may also help lower your bad cholesterol and improve symptoms of arthritis.

The majority of studies of intermittent fasting in humans have considered whether intermittent fasting can be a potential strategy to reduce weight and correct adverse metabolic parameters amongst obese and overweight subjects 33). This is important since the problems of long term adherence to continuous calorie restriction for weight management are well known 34). Losing weight and being physically active help lower your risk of obesity-related diseases, such as diabetes, sleep apnea and some types of cancer. For these diseases, intermittent fasting seems to be about as beneficial as any other type of diet that reduces overall calories. Johnson et al. 35) undertook the first trial of intermittent fasting for weight loss amongst 10 obese subjects with asthma which tested alternate days of an 85% energy restricted low carbohydrate diet regimen. This study reported beneficial reductions in serum cholesterol and triglycerides, markers of oxidative stress (8-isoprostane, nitrotyrosine, protein carbonyls, and 4-hydroxynonenal adducts) and inflammation (serum tumor necrosis factor-α) 36). Circulating ketone levels were also elevated on the fasting days 37). In more recent 27 clinical trials, intermittent fasting resulted in weight loss, ranging from 0.8% to 13.0% of baseline body weight 38). Weight loss occurred regardless of changes in overall caloric intake. In the studies of 2 to 12 weeks’ duration, body mass index (BMI) decreased, on average, by 4.3% to a median of 33.2 kg/m². Therefore intermittent fasting shows promise as a primary care intervention for obesity, but little is known about long-term sustainability and health effects. Longer-duration studies are needed to understand how intermittent fasting might contribute to effective weight-loss strategies. Symptoms such as hunger remained stable or decreased, and no adverse events were reported. While intermittent fasting is a moderately successful strategy for weight loss, it shows promise for improving glycemic control, although it does pose a potential risk of hypoglycemia. However, to lose weight and keep it off, the best strategy is to adopt healthy eating and exercise habits that you enjoy so you can stick with them over time.

To get the benefits of intermittent fasting, you need to fast for at least 12 hours. That’s how long it takes your body to switch from using glucose for energy to using fat for energy. Additionally, it will take your body a while to get used to this new eating schedule. So don’t expect results right away. You may need to wait between 2 and 4 weeks to see or feel any results.

It may take 2 to 4 weeks for your body to get used to eating on an intermittent fasting schedule. During those first few weeks, you may have headaches and feel hungry, grouchy, or tired. Know you may feel this way before you start and make a plan to push through these feelings. After a few weeks, your body will get used to this eating pattern and those symptoms should go away. In the end, many people say that feel better following an intermittent fasting lifestyle.

Weight loss supplements

Currently available food supplements feature several purported mechanisms of action, such as improvement of carbohydrate metabolism, increased lipolysis or energy expenditure, and reduced hunger. Most of the cited dietary supplements were also proven to exert anti-inflammatory and antioxidant effects, possibly aiding the resolution of low-grade chronic inflammation typical of weight excess and metabolic derangements (see Figure 4). To inhibit the absorption of nutrients, researchers suggest using phaseolus vulgaris extract (PVE) at a dosage of 3000 mg (1000 mg per meal) daily, and green tea derived epigallocatechin (EGCG) at a dosage of 500 mg daily. In order to reduce appetite and possibly increase energy expenditure, researchers propose the use of coffee derived caffeine (300 mg/daily) and chlorogenic acid (CGA) (200 mg/daily). Chili pepper derived capsaicinoids or capsinoids may also be considered, at a dosage of 10 mg and 3 mg, respectively, together with L-Carnitine at a dosage of 2 g daily, that can also increase fat mobilization. Similarly enhancing beta oxidation and inhibiting lipogenesis, resveratrol and conjugated linoleic acid (CLA) may be considered, given their proven efficacy and absence of reported adverse events, at a dosage of 200 mg and 4 g daily, respectively. Finally, carbohydrate metabolism may be improved with glucose lowering lipoic acid at a dosage of 600 mg daily, with its long-standing history in the treatment of type 2 diabetes.

A specifically designed, placebo-controlled study investigating the proposed food supplements combination for weight loss purposes is now needed, in order to confirm the safety profile, the absence of detrimental interactions between the suggested compounds, and the presence of an additive or synergistic effect possibly aiding weight loss in a safe and effective way 39).

Figure 4. Weight loss supplements

Weight loss supplements

Footnotes: Proposed food supplement combination leveraging multiple mechanisms of action to aid weight loss and metabolism improvement based on the current state of the art. Green tea was shown to inhibit pancreatic lipase, amylase, and glucosidase in the gastrointestinal tract reducing the absorption of nutrients and leading to the presence of undigested carbohydrates in the GI tract, in turn driving the microbiota to produce short-chain fatty acids (SCFA). Through an AMPK dependent mechanism, it also inhibits lipogenesis and induces lipolysis. Phaseolus vulgaris extract (PVE) contains phaseolin, an α-amylase inhibitor whose function impairs the absorption of carbohydrates. Caffeine suppresses hunger and stimulates energy expenditure through increased excitability of the sympathetic nervous system (SNS), increased fat oxidation and Brown Adipose Tissue (BAT) activation. Capsaicinoids activate the Transient Receptor Potential Channel Vanilloid type-1 (TRPV1) leading to Glucagon like peptide 1 (GLP-1) release, increased fat oxidation, increased Sirtuin-1 (SIRT-1) expression. They also suppress ghrelin release and increase adiponectin, PPARα and PGC-1α expression. They finally regulate gluconeogenesis and glycogen synthesis genes improving insulin resistance. L-Carnitine was shown to improve insulin resistance, increase acetyl-coenzyme A and glucose supply to the brain leading to increased energy expenditure; it facilitates activated long chain fatty acids transportation into mitochondria, playing an important role in β-oxidation. It also modulates lipid metabolism. Resveratrol increases SIRT-1 expression, decreases adipogenesis and viability in maturing preadipocytes and modulates lipid metabolism in mature adipocytes. Conjugated linoleic acid (CLA) decreases the size of adipocytes, alters adipocyte differentiation, regulates lipid metabolism and activates of PPAR-γ receptors. Lipoic acid increases GLUT4 expression on the cell membrane of skeletal muscle and adipocyte cells leading to increased glucose uptake, hence improved glucose tolerance, chlorogenic acid (CGA).

[Source 40) ]

Table 5. Food supplements with a primary impact on nutrients absorption

Food Supplement DosageMechanisms of ActionQuality of Evidence Side Effects Recommendation
Green Tea 100–460 mg/daylipase, amylase, glucosidase inhibition *#; gut microbiota modification *#moderateNonePossibly recommended
Ginseng 100 mg–18 g/daylipase inhibition *#; appetite hormonwhie levels modification *lowNoneUndetermined recommendation
White Kidney Bean 1–3 g/dayα-amylase inhibition *#; antioxidant *, anticarcinogenic *#, anti-inflammatory*#, glucose lowering *#, and cardioprotective properties *#moderateLectin’s toxicity (abstent in phaseolus vulgaris extracts)Possibly recommended
Chitosan 1–4.5 g/dayabsorption of dietary fats inhibition *#; decreased lipid peroxidation; adipogenesis inhibition *lowGastrointestinal discomfort and bloatingUndetermined recommendation
β-Glucans 5–9 g/daylipid and carbohydrate absorption inhibition *#; satiety induction *#; PYY-NPY axis activation *#lowNoneUndetermined recommendation
Psyllium 3–10.5 g/daycarbohydrate absorption inhibition *#; decreased serum lipids *#; delayed gastric emptying *#; glucose control *#; satiety induction *#lowGastrointestinal discomfort and bloatingUndetermined recommendation
Glucomannan 2–3 g/daydelayed gastric emptying *#, increased satiety *#; decreased post-prandial glucose concentrationlowNoneUndetermined recommendation
Guar Gum 9–30 g/dayincreased postprandial fullness #, appetite and food intake reduction *#lowGastrointestinal discomfort, bloating, diarrheaUndetermined recommendation
Agar 180 g/daydelayed gastric emptying #; increased satiety *#lowNoneUndetermined recommendation
Inulin 8–30 g/daycarbohydrate absorption inhibition *#; gut microbiota modulation *#; increased satiety *#lowNoneUndetermined recommendation

Footnote: * denotes preclinical evidence; # denotes clinical evidence

[Source 41) ]

Table 6. Food supplements with a primary impact on appetite regulation

Food Supplement DosageMechanisms of ActionQuality of Evidence Side EffectsRecommendation
Caralluma1 g/dayfatty acid synthesis inhibition and enhanced fatty acid oxidation *; ghrelin/neuropeptide Y expression inhibition *#lowNoneUndetermined recommendation
Spirulina1–4.5 g/daydecreased appetite *#; adipogenesis inhibition *; browning induction *lowNoneUndetermined recommendation
Whey protein∼100–600 g/weekincreased satiety hormones; decreased appetite; enhanced fat mass oxidation; enhanced lean mass preservation *#moderateNonePossibly recommended
Coffee, caffeine and chlorogenic acids60 mg–1000 g/dayhunger suppression; energy expenditure stimulation; increased fat oxidation and brown adipose tissue activation *#moderateNonePossibly recommended
Bitter orange10–400 mg/daysuppressed appetite *#; energy expenditure and lipolysis increase *#lowNoneUndetermined recommendation
Guarana240–285 mg/daydecreased appetite #; increased energy expenditure and fat oxidation *#; adipogenesis inhibition *; browning induction *lowGastrointestinal discomfort; insomnia, migraine, tachycardiaUndetermined recommendation

Footnote: * denotes preclinical evidence; # denotes clinical evidence

[Source 42) ]

Table 7. Food supplements with a primary impact on energy expenditure modulation

Food SupplementDosageMechanisms of ActionQuality of Evidence Side EffectsRecommendation
Capsaicin, capsaicinoids and capsinoids10–30 mg/daybrowning, thermogenesis, fat oxidation *#, energy expenditure induction #lowGastrointestinal discomfort and diarrheaUndetermined recommendation
Curcumin70 mg–12 g/dayadipogenesis inhibition *; insulin-sensitizing and anti-inflammatory properties *#lowGastrointestinal discomfort, headache, urticariaUndetermined recommendation
L-Carnitine10 mg–4 g/dayincreased energy expenditure and fat oxidation *#; improved insulin resistance *#; modulation of regulators of lipid catabolism or adipogenesis *; induction of satiety *#lowNoneUndetermined recommendation

Footnote: * denotes preclinical evidence; # denotes clinical evidence

[Source 43) ]

Table 8. Food supplements with a primary impact on fat metabolism

Food Supplement DosageMechanisms of ActionQuality of Evidence Side EffectsRecommendation
Pyruvate5–44 g/dayreduced insulin level and increased acetylCoA concentrations *#lowNoneUndetermined recommendation
Dyacilglycerol1.1–1.2 g/dayenhanced fat oxidation *#; reduced postprandial triglycerides *#moderateNonePossibly recommended
Licorice300–900 mg/dayreduced serum lipids *#; improved hepatic steatosis through beta-oxidation induction *#lowIncreased blood pressure, hypernatremiaNot recommended
Garcinia Gambogia400–2400 mg/daydecreased lipogenesis and increased lipolysis *lowHepatotoxicity, diarrheaNot recommended
Resveratrol75–2000 mg/daydecreased adipogenesis; increased lipolysis;reduced lipogenesis *#lowNonePossibly recommended
Conjugated linoleic acid1.5–6.8 g/daydecreased adipocytes size; inhibited adipogenesis; reducted lipogenesis; induced browining *; gut microbiota modification *#;lowOccasional gastrointestinal discomfortPossibly recommended
Aloe vera588–700 mg/dayImproved glucose and lipid metabolism *#; reduced oxidative stress * ; inhibited lipogenesis *lowNoneUndetermined recommendation
Flaxseed20–50 g/dayincreased saxiety *# and lipolysis *; inhibited lipogenesis *lowNonePossibly recommended
Grapefruit81–142 mg/dayimproved glycemic control, enhanced insulin secretion and inhibited gluconeogenesis *#; increased fat oxidation and reduced lipogenesis *lowPossible alteration of several drugs metabolismUndetermined recommendation

Footnote: * denotes preclinical evidence; # denotes clinical evidence

[Source 44) ]

Table 9. Food supplements with a primary impact on carbohydrate metabolism

Food Supplement DosageMechanisms of ActionQuality of Evidence Side EffectsRecommendation
Mangosteen200–400 mg/dayinhibition of pancreatic lipase and fatty acid synthase *; improved glucose metabolism *#LowNoneUndetermined recommendation
Chromium157–1000 μg/dayEnergy expenditure increase *#; appetite suppression *#; improved glucose metabolism *#ModerateDiarrhea, vertigo, headache, urticariaUndetermined recommendation
Lipoic Acid300–2400 mg/dayimproved glucose metabolism *#; appetite suppression *#; increase of lipolysis and reduction of lipogenesis *LowGastrointestinal discomfort, urticaria, hypoglycemiaUndetermined recommendation

Footnote: * denotes preclinical evidence; # denotes clinical evidence

[Source 45) ]

Weight loss exercise

Negative energy balance and subsequent weight loss can be achieved by either reducing energy intake or increasing energy expenditure usually by exercise. These literatures 46), 47) support that the majority of the weight loss from combined exercise training and caloric restriction can be attributed to caloric restriction. However, exercise-induced weight loss is usually small, and smaller than expected from an exercise-induced increase in energy expenditure 48). Exercise has been shown to prevent regain after weight loss 49). When you lose body weight by cutting calories, you focus on losing fat mass but you are also losing muscle mass (lean body mass) at the same time. Here’s where exercise come in. Studies have shown a slowing of muscle mass loss whenever physical activity is part of your weight loss plan. However, more research is needed to determine what exercise are most effective at reducing the compensatory increase in energy intake in response to an exercise-induced increase in energy expenditure 50).

The present American College of Sports Medicine recommendations for physical activity to maintain health 51) and promote weight loss 52) are summarized below.

American College of Sports Medicine recommendations for physical activity for Weight Loss and Prevention of Weight Regain for Adults 53):

  • Maintain and improving health: 150 minutes/week
  • Prevention of weight gain: 150 – 250 minutes/week
  • Promote clinically significant weight loss: 225 – 420 minutes/week
  • Prevention of weight gain after weight loss: 200 – 300 minutes/week

The American College of Sports Medicine position stand on physical activity intervention strategies to promote weight loss and weight regain emphasize the distinction between the minimum levels of physical activity to maintain health (150 minutes per week) and higher levels of physical activity to prevent weight regain (200 minutes per week) 54). Therefore, obese individuals who have successfully lost weight require a substantial amount of physical activity to maintain this weight loss. As indicated in theAmerican College of Sports Medicine position stand 55), several major limitations to research of physical activity on weight regain exist including the observational and the retrospective nature of the existing literature from randomized trials. However, several studies in this area deserve mentioning. Using data from a physical activity weight loss study, Jakicic et al. 56) observed a dose response between the amount of self-reported physical activity per week and long-term success with weight loss at 18 months of intervention (composed of caloric restriction and exercise training). Adults who exercised greater than 200 minutes per week (−13.1 kg) lost more weight compared to those who exercised between 150-199 min per week (−8.5 kg), and those that exercised less than 150 minutes week (−3.5 kg) 57). A different study by Jakicic et al. 58) observed similar findings in post hoc analyses of a weight loss intervention composed of both caloric restriction and exercise training in women. After 12 months of intervention, women with greater than 200 minutes/week (13.6%) had maintained significantly greater percentage of weight loss compared to those who had exercised at 150-199 minutes/week (9.5%), and less than 150 min/week (4.7%) 59). Lastly, Andersen et al. 60) evaluated the effect of low-fat diet (1200 kcals/day) in combination with either structured aerobic exercise or lifestyle activity (patients were advised to increase their physical activity to recommended levels), and both groups lost approximately 8 kg of weight following 16 weeks of intervention. Weight maintenance was monitored for 1 year after the intervention, and those who were the most active lost additional weight (1.9 kg) whereas the group that was the least active regained a substantial amount of weight (4.9 kg) 61). These data suggest that physical activity has an important role in the amount of weight regain following successful weight loss 62). Therefore, patients attempting to reduce recidivism after weight loss should engage in physical activity levels above 200 minutes/week 63).

Exercise and weight maintenance

The American College of Sports Medicine position stand on physical activity intervention strategies to promote weight loss and weight regain emphasize the distinction between the minimum levels of physical activity to maintain health (150 minutes per week) and higher levels of physical activity to prevent weight regain (200 minutes per week) 64). Therefore, obese individuals who have successfully lost weight require a substantial amount of physical activity to maintain this weight loss 65). As indicated in the American College of Sports Medicine position, several major limitations to research of physical activity on weight regain exist including the observational and the retrospective nature of the existing literature from randomized trials 66). However, several studies in this area deserve mentioning. Using data from a physical activity weight loss study, Jakicic et al. 67) observed a dose response between the amount of self-reported physical activity per week and long-term success with weight loss at 18 months of intervention (composed of caloric restriction and exercise training). Adults who exercised greater than 200 minutes per week (−13.1 kg) lost more weight compared to those who exercised between 150-199 min per week (−8.5 kg), and those that exercised less than 150 minutes week (−3.5 kg) 68). A different study by Jakicic et al. 69) observed similar findings in post hoc analyses of a weight loss intervention composed of both caloric restriction and exercise training in women. After 12 months of intervention, women with greater than 200 min/week (13.6%) had maintained significantly greater percentage of weight loss compared to those who had exercised at 150-199 min/week (9.5%), and less than 150 min/week (4.7%). Lastly, Andersen et al. 70) evaluated the effect of low-fat diet (1200 kcals/day) in combination with either structured aerobic exercise training or lifestyle activity (patients were advised to increase their physical activity to recommended levels), and both groups lost approximately 8 kg of weight following 16 weeks of intervention. Weight maintenance was monitored for 1 year after the intervention, and those who were the most active lost additional weight (1.9 kg) whereas the group that was the least active regained a substantial amount of weight (4.9 kg). These data suggest that physical activity has an important role in the amount of weight regain following successful weight loss. Therefore patients attempting to reduce recidivism after weight loss are encouraged to engage in physical activity levels above 200 minutes/week 71).

Best exercise to lose weight

Extensive scientific evidence supports the importance of recommending that all Americans should engage in regular physical activity to improve overall health and to reduce the risk of many health problems. Physical activity is a leading example of how lifestyle choices have a profound effect on health. Recently identified benefits of physical activity:

  • Improved bone health and weight status for children ages 3 through 5 years.
  • Improved cognitive function for youth ages 6 to 13 years.
  • Reduced risk of cancer at a greater number of sites.
  • Brain health benefits, including possible improved cognitive function, reduced anxiety and depression risk, and improved sleep and quality of life.
  • For pregnant women, reduced risk of excessive weight gain, gestational diabetes, and postpartum depression.
  • For older adults, reduced risk of fall-related injuries.
  • For people with various chronic medical conditions, reduced risk of all-cause and disease-specific mortality, improved physical function, and improved quality of life.

The four main types of physical activity are aerobic, muscle-strengthening, bone-strengthening, and stretching. Aerobic activity is the type that benefits your heart and lungs the most. Table 10 summarizes the expected weight change from different exercise training programs in obese patients and describe the overall likelihood for clinically significant weight loss.

A well-known physiologic effect of exercise or physical activity is that it expends energy. A metabolic equivalent of task or MET, is a unit useful for describing the energy expenditure of a specific physical activity. A MET is the ratio of the rate of energy expended during an activity to the rate of energy expended at rest. For example, 1 MET is the rate of energy expenditure while at rest. A 4 MET activity expends 4 times the energy used by the body at rest. If a person does a 4 MET activity for 30 minutes, they have done 4 x 30 = 120 MET-minutes (or 2.0 MET-hours) of physical activity. A person could also achieve 120 MET-minutes by doing an 8 MET activity for 15 minutes.

Table 10. Expected initial weight loss and possibly of producing clinically significant weight loss from different modalities of exercise training

Exercise modalityWeight LossClinically significant weight loss
Pedometer-based step goal Range: 0 to 1 kg of weight lossUnlikely
Aerobic Exercise Training only Range: 0 to 2kg of weight lossPossible, but only with extremely high exercise volumes
Resistance Training only NoneUnlikely
Aerobic and Resistance training only Range: 0 to 2kg of weight lossPossible, but only with extremely high volumes of aerobic exercise training
Caloric restriction combined with aerobic exercise training Range: −9 kg to −13 kgPossible
[Source 72) ]

Aerobic exercise

Aerobic exercise is also called endurance activity, moves your large muscles, such as those in your arms and legs. Running, swimming, walking, bicycling, dancing, and doing jumping jacks are examples of aerobic activity. Aerobic exercise makes your heart beat faster than usual. You also breathe harder during this type of activity. Over time, regular aerobic activity makes your heart and lungs stronger and able to work better.

Below are examples of aerobic activities. Depending on your level of fitness, they can be light, moderate, or vigorous in intensity:

  • Pushing a grocery cart around a store
  • Gardening, such as digging or hoeing that causes your heart rate to go up
  • Walking, hiking, jogging, running
  • Water aerobics or swimming laps
  • Bicycling, skateboarding, rollerblading, and jumping rope
  • Ballroom dancing and aerobic dancing
  • Tennis, soccer, hockey, and basketball

You can do aerobic activity with light, moderate, or vigorous intensity. Moderate- and vigorous-intensity aerobic exercises are better for your heart than light-intensity activities. However, even light-intensity activities are better than no activity at all.

The level of intensity depends on how hard you have to work to do the activity. To do the same activity, people who are less fit usually have to work harder than people who are more fit. So, for example, what is light-intensity activity for one person may be moderate-intensity for another.

Absolute rates of energy expenditure during physical activity are commonly described as light, moderate, or vigorous intensity. Energy expenditure is expressed by multiples of the metabolic equivalent of task (MET), where 1 MET is the rate of energy expenditure while sitting at rest.

  • Light-intensity activity
    • Light-intensity activities are common daily activities that don’t require much effort.
    • Light-intensity activity is non-sedentary waking behavior that requires less than 3.0 METs; examples include walking at a slow or leisurely pace (2 miles per hour [mph] or less), cooking activities, or light household chores.
  • Moderate-Intensity activity
    • Moderate-intensity activities make your heart, lungs, and muscles work harder than light-intensity activities do.
    • On a scale of 0 to 10, moderate-intensity activity is a 5 or 6 and produces noticeable increases in breathing and heart rate. A person doing moderate-intensity activity can talk but not sing.
    • Moderate-intensity activity requires 3.0 to less than 6.0 METs; examples include walking briskly (2.5 to 4 mph), playing doubles tennis, or raking the yard.
  • Vigorous-Intensity activity
    • Vigorous-intensity activities make your heart, lungs, and muscles work hard. On a scale of 0 to 10, vigorous-intensity activity is a 7 or 8. A person doing vigorous-intensity activity can’t say more than a few words without stopping for a breath. Vigorous-intensity activity examples include jogging, running, carrying heavy groceries or other loads upstairs, shoveling snow, or participating in a strenuous fitness class. Many adults do no vigorous-intensity physical activity.
    • Vigorous-intensity activity requires 6.0 or more METs.

The literature is clear that caloric restriction is more likely to result in clinically significant weight loss compared to aerobic exercise training alone. Current American College of Sports Medicine recommendations state that exercise programs need to exceed 225 minutes/per week in order to possibly induce clinically significant weight loss 73). Supervised exercise training studies which have demonstrated clinically significant weight loss with aerobic exercise training (without caloric restriction) have far exceeded the minimum levels of physical activity according to public health definitions 74). Ross et al. 75) observed an 8% weight loss in obese men after 12 weeks of aerobic exercise training with no alterations in dietary habits (daily exercise sessions of 700 kcals). In a different study, Ross et al. 76) observed an 6.8% weight loss in premenopausal women (BMI>27) following 14 weeks of aerobic exercise training with an energy expenditure of 500 kcals per session. In the Midwest Exercise Trial, Donnelly et al. 77) (n=131) observed a 5.3% weight loss in men after 16 weeks of aerobic exercise training at approximately 2,000 kcals per week. In contrast, the women in the exercise group did not have a significant change in weight (0.7 kg) following the intervention, but the exercise program prevented the weight gain observed in the control group (2.9 kg.) Thus, clinically significant weight loss is possible with aerobic exercise training without caloric restriction, but it requires a high exercise training volume 78). For the general population, these exercise training volumes may not be practical or sustainable.

The following studies represent the strongest research design to evaluate changes in weight from aerobic exercise program as they have a large sample size of overweight or obese individuals at baseline, supervised exercise program sessions, strong adherence to their aerobic exercise program program, and comparison of weight change against a control group. The Dose Response to Exercise in Women study (n=464) observed no significant changes in body weight in postmenopausal women exercising at 50% (−0.4 kg), 100% (−2.2 kg) and 150% (−0.6 kg) of public health guidelines for 6 months despite greater than 89% adherence in all exercise program groups 79). The Inflammation and Exercise study (n=129) observed no significant change in body weight (−0.4 kg) compared to the control group (0.1 kg) after 4 months of exercise program in adults with elevated C-reactive protein (CRP) levels at baseline 80). The Studies of a Targeted Risk Reduction Intervention through Defined Exercise study (n=84) observed significant, but minimal weight loss in those exercising at low amount/moderate intensity (−0.6 kg, 176 min/week), low amount/high intensity (−0.2 kg, 117 min/week ), or high amount high intensity (−1.5 kg, 171 minutes/week) following 6 months of aerobic exercise program 81). The Diabetes Aerobic and Resistance Exercise study (n= 251) observed significant weight loss in the aerobic exercise program group (−0.74 kg) compared to the control group after 22 weeks of intervention in adults with type 2 diabetes mellitus 82).

Thus, overweight and obese adults who adhere to an exercise program consistent with public health recommendations without a dietary plan involving caloric restriction can expect to experience weight loss in a range of no weight loss to approximately 2 kgs 83). However, patients should know that the chances of substantial weight loss are unlikely at these exercise program levels without caloric restriction 84). Regardless of the amount of weight loss, numerous health benefits occur in the absence of weight loss, and that maintenance of an active lifestyle will reduce the risk of future weight gain 85). An important limitation of the present data in this area is that long-term (> 1 year) and time-course studies are not currently available.

Individuals who lose less weight than expected based on their exercise training energy expenditure have been termed “weight compensators.” Several studies have examined weight compensation after aerobic exercise training. King et al. 86) observed increased energy intake and increased fat intake in weight compensators compared to those that did not compensate for weight loss. Using data from the Dose Response to Exercise in Women study 87), Church et al. 88) examined weight compensation in postmenopausal women who were required to perform exercise training at 50%, 100% and 150% of public health recommendations, and restricted the analysis to those who were 85% compliant to exercise training. The authors observed that the most weight compensation (less weight loss achieved than predicted from exercise training alone) occurred in the women exercising at 150% of the recommended volume 89). In fact, the amount of actual weight loss achieved in women exercising at 50% (−1.4 kg) and 150% (−1.5 kg) of the physical activity recommendations were virtually identical to each other despite the greater level of energy weekly energy expenditure in the 150% group 90). Thomas et al. 91) performed an analysis of weight change from 15 aerobic exercise training interventions, and concluded that the major factors limiting the expected weight loss from aerobic exercise training were dietary compensation and low aerobic exercise training dose. At the present time, evidence is limited to explain whether other factors of the energy balance equation, including compensatory changes in non-exercise physical activity (except for perhaps older adults), resting metabolic rate, movement efficiency, or changes in lean mass, are responsible for weight compensation with exercise training.

Muscle-strengthening exercises

Muscle-strengthening exercises improve your strength, power, and endurance of your muscles. Doing pushups and situps, lifting weights, climbing stairs, and digging in the garden are examples of muscle-strengthening activities.

Resistance exercise training and isometric exercises are important training program that have many health benefits including increasing/maintaining muscular strength with aging (prevention of sarcopenia) and preserving bone mineral density 92). Although, resistance exercise training alone contributes to the reduction of body fat, the effect on overall weight loss is minimal 93). In the Health Benefits of Aerobic and Resistance Training study, Church et al. 94) observed no significant change (−0.3 kg) in weight in the resistance exercise training group (n=73) compared to a control group after the 9 month intervention. In the Diabetes Aerobic and Resistance Exercise trial 95), no significant difference was observed between the resistance exercise training group and the control group (0.3 kg). Bateman et al. 96) (n= 86) observed no significant change in weight (0.07 kg) following 8 months of intervention in the Studies of a Targeted Risk Reduction Intervention Through Defined Exercise study. Overall, little evidence exists that resistance training alone promotes weight loss.

Very few randomized controlled trials have explored whether the combination of both aerobic and resistance exercise training leads to a greater reduction in body weight compared to aerobic exercise training alone. The available evidence from large randomized controlled trials suggests similar weight losses after participating in a program composed of aerobic exercise training or combined aerobic and resistance exercise training 97). However, combined programs may have enhanced effects for other health indicators such as glucose control. Observations from both the Health Benefits of Aerobic and Resistance Training 98) and Diabetes Aerobic and Resistance Exercise trials 99) suggest that an exercise training program composed of both resistance and aerobic exercise training promotes greater changes in hemoglobin A1C (HbA1c) compared to aerobic exercise training alone in adults with type 2 diabetes mellitus.

Bone-strengthening exercises

With bone-strengthening activities, your feet, legs, or arms support your body’s weight, and your muscles push against your bones. This helps make your bones strong. Running, walking, jumping rope, and lifting weights are examples of bone-strengthening exercises.

Muscle-strengthening and bone-strengthening activities also can be aerobic, depending on whether they make your heart and lungs work harder than usual. For example, running is both an aerobic activity and a bone-strengthening activity.

Stretching exercises

Stretching helps improve your flexibility and your ability to fully move your joints. Touching your toes, doing side stretches, and doing yoga exercises are examples of stretching.

Pedometers-based step exercises

Pedometers are devices that count the number of steps that an individual accumulates throughout the day 100). The current consensus states that obtaining less than 5,000 steps per day is indicative of sedentary behavior, whereas greater than 8,000 or 10,000 steps suggests a more active lifestyle 101). You can utilize pedometers to assess your current physical activity habits, and as a tool for increasing your physical activity levels. Pedometer-based interventions where sedentary participants increase physical activity levels to 10,000 steps or 2000-4,000 step/day above baseline levels have shown some positive effects for weight loss; however, in general weight loss tends to very modest (<2 kg) 102). Richardson et al. 103) performed a meta-analysis on pedometer-based interventions without caloric restriction (median duration: 16 weeks), and observed that pooled estimated change in weight was −1.3 kg. Bravata et al. 104) performed a meta-analysis regarding the physiological effects of pedometer-based interventions on risk factors for cardiovascular disease, and has observed significant reductions in BMI (−0.38 kg/m²), systolic blood pressure (−3.8 mmHg), diastolic blood pressure (−0.3 mmHg), but no significant reduction in cholesterol, triglyceride, or fasting glucose levels. Although, asking a participant to walk a certain amount of steps can promote favorable changes in cardiovascular disease risk factors and may provide minimal weight loss, little empirical evidence exists that a pedometer-based program alone without caloric restriction can promote clinically significant weight loss 105).

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