Weight-loss and 

Nutrition Myths

 WIN Weight-control Information Network

“Lose 30 pounds in 30 days!” 

“Eat as much as you want and still lose weight!”

“Try the thigh buster and lose inches fast!” 

Have you heard these claims before? A large number 

of diets and tools are available, but their quality 

may vary. It can be hard to know what to believe. 

This fact sheet may help. Here, we discuss myths and 

provide facts and tips about weight loss, nutrition, 

and physical activity. This information may help you 

make healthy changes in your daily habits. You can 

also talk to your health care provider. She or he can 

help you if you have other questions or you want 

to lose weight. A registered dietitian may also give 

you advice on a healthy eating plan and safe ways 

to lose weight and keep it off.

Weight-loss and Diet Myths

Myth: Fad diets will help me lose weight and 

keep it off. 

Fact: Fad diets are not the best way to lose weight 

and keep it off. These diets often promise quick 

weight loss if you strictly reduce what you eat or 

avoid some types of foods. Some of these diets may 

help you lose weight at first. But these diets are hard 

to follow. Most people quickly get tired of them 

and regain any lost weight. 

Fad diets may be unhealthy. They may not provide 

all of the nutrients your body needs. Also, losing 

more than 3 pounds a week after the first few weeks 

may increase your chances of developing gallstones 

(solid matter in the gallbladder that can cause pain). 

Being on a diet of fewer than 800 calories a day for 

a long time may lead to serious heart problems. 

U.S. Department of Health 

and Human Services

Healthy habits may help you lose 

weight.

 Make healthy food choices. Half of your 

plate should be fruits and veggies. 

 Eat small portions. Use a smaller plate, 

weigh portions on a scale, or check the 

Nutrition Facts label for details about 

serving sizes (see page 3). 

 Build exercise into your daily life. Garden, 

go for family walks, play a pickup game of 

sports, start a dance club with your friends, 

swim, take the stairs, or walk to the grocery 

store or work.

Combined, these habits may be a safe, healthy 

way to lose weight and keep it off.

TIP: Research suggests that safe weight loss 

involves combining a reduced-calorie diet with 

physical activity to lose 1/2 to 2 pounds a week 

(after the first few weeks of weight loss). Make 

healthy food choices. Eat small portions. Build 

exercise into your daily life. Combined, these 

habits may be a healthy way to lose weight and 

keep it off. These habits may also lower your 

chances of developing heart disease, high blood 

pressure, and type 2 diabetes.
2

Myth: Carbs are fattening. I should limit them 

when trying to lose weight. 

Fact: Carbohydrates (carbs) are the body’s main 

source of fuel for energy. You don’t have to limit all 

carbs to lose weight. There are two main types of 

carbs: simple carbs (sugars) and complex carbs 

(starches and fiber). Foods that are high in complex 

carbs—like fruits, veggies, and whole grains—

provide a healthy supply of fiber, minerals, and 

vitamins. But simple carbs from cake, candy, cookies, 

and sugar-sweetened desserts and drinks (including 

alcohol) have many calories and few nutrients. 

Government dietary guidelines advise eating plenty 

of unrefined grains, like brown rice and wholewheat bread, cereal, and pasta. They also suggest 

that fruit and veggies should make up half of what 

is on your plate. The Resources section at the end of 

this fact sheet offers helpful links to these guidelines 

and the ChooseMyPlate website, which provides 

information, tips, and tools on healthy eating. 

TIP: To lose weight, reduce the number of 

calories you take in and increase the amount of 

physical activity you do each day. Create a healthy 

eating plan that mixes carbs, fat, and protein: 

 Eat a mix of fat-free or low-fat milk and milk 

products, fruits, veggies, and whole grains. 

 Limit added sugars, cholesterol, salt (sodium), 

and saturated fat. 

 Eat low-fat protein: beans, eggs, fish, lean meats, 

nuts, and poultry. 

Meal Myths

Myth: Some people can eat whatever they want 

and still lose weight.

Fact: To lose weight, you need to burn more calories 

than you eat and drink. Some people may seem to 

get away with eating any kind of food they want and 

still lose weight. But those people, like everyone, 

must use more energy than they take in through 

food and drink to lose weight. 

A number of factors such as your age, genes, 

medicines, and lifestyle habits may affect your 

weight. If you would like to lose weight, speak with 

your health care provider about factors that may 

affect your weight. Together, you may be able to 

create a plan to help you reach your weight and 

health goals.

Eat the rainbow!

When making half 

of your plate fruits 

and veggies, 

choose foods with 

vibrant colors that 

are packed with 

fiber, minerals, 

and vitamins. 

 Red: bell peppers, cherries, cranberries, 

onions, red beets, strawberries, tomatoes, 

watermelon

 Green: avocado, broccoli, cabbage, 

cucumber, dark lettuce, grapes, honeydew, 

kale, kiwi, spinach, zucchini 

 Orange and yellow: apricots, bananas, 

carrots, mangoes, oranges, peaches, squash, 

sweet potatoes 

 Blue and purple: blackberries, blueberries, 

grapes, plums, purple cabbage, purple 

carrots, purple potatoes

For more tips on healthy eating, see the 

Resources section for helpful links to federally 

approved dietary guidelines and MyPlate.
3

TIP: When trying to lose weight, you can still 

eat your favorite foods as part of a healthy eating 

plan. But you must watch the total number of 

calories that you eat. Reduce your portion sizes 

(see the sidebar to understand portions and 

servings). Find ways to limit the calories in your 

favorite foods. For example, you can bake foods 

rather than frying them. Use low-fat milk in place 

of cream. Make half of your plate fruits and 

veggies.

Myth: “Low-fat” or “fat-free” means no calories.

Fact: A serving of low-fat or fat-free food may 

be lower in calories than a serving of the full-fat 

product. But many processed low-fat or fat-free foods 

have just as many calories as the full-fat versions 

of the same foods—or even more calories. These 

foods may contain added flour, salt, starch, or sugar 

to improve flavor and texture after fat is removed. 

These items add calories.

TIP: Read the Nutrition Facts (see Figure 1) on a 

food package to find out how many calories are 

in a serving. Check the serving size, too—it may 

be less than you are used to eating.

FIGURE 1. Nutrition Facts Label

Start Here

Check Calories

Limit these 

Nutrients

Get Enough of 

these Nutrients

Adapted from http://www.fda.gov/Food/IngredientsPackagingLabeling/

LabelingNutrition/ucm274593.htm.

What is the difference between a 

serving and a portion?

The U.S. Food and Drug Administration (FDA) 

Nutrition Facts label appears on most packaged 

foods (see Figure 1). It tells you how many 

calories and servings are in a box or can. The 

serving size varies from product to product. 

A portion is how much food you choose to eat 

at one time, whether in a restaurant, from a 

package, or at home. Sometimes the serving 

size and portion size match; sometimes they 

do not. 

You can use the Nutrition Facts label

 to track your calorie intake and number of 

servings 

 to make healthy food choices by serving 

smaller portions and selecting items lower 

in fats, salt, and sugar and higher in fiber 

and vitamins 

For more guidance on reading food labels, 

check out the web page How to Use and 

Understand the Nutrition Facts Label listed 

under Resources.
4

Myth: Fast foods are always an unhealthy choice. 

You should not eat them when dieting.

Fact: Many fast foods are unhealthy and may affect 

weight gain. However, if you do eat fast food, choose 

menu options with care. Both at home and away, 

choose healthy foods that are nutrient rich, low in 

calories, and small in portion size.

TIP: To choose healthy, low-calorie options, check 

the nutrition facts. These are often offered on the 

menu or on restaurant websites. And know that 

the nutrition facts often do not include sauces 

and extras. Try these tips:

 Avoid “value” combo meals, which tend to have 

more calories than you need in one meal.

 Choose fresh fruit items or nonfat yogurt for 

dessert. 

 Limit your use of toppings that are high in 

fat and calories, like bacon, cheese, regular 

mayonnaise, salad dressings, and tartar sauce.

 Pick steamed or baked items over fried ones.

 Sip on water or fat-free milk instead of soda. 

Myth: If I skip meals, I can lose weight. 

Fact: Skipping meals may make you feel hungrier 

and lead you to eat more than you normally would 

at your next meal. In particular, studies show a link 

between skipping breakfast and obesity. People who 

skip breakfast tend to be heavier than people who 

eat a healthy breakfast. 

TIP: Choose meals and snacks that include a 

variety of healthy foods. Try these examples:

 For a quick breakfast, make oatmeal with low-fat 

milk, topped with fresh berries. Or eat a slice of 

whole-wheat toast with fruit spread.

 Pack a healthy lunch each night, so you won’t be 

tempted to rush out of the house in the morning 

without one. 

 For healthy nibbles, pack a small low-fat yogurt, 

a couple of whole-wheat crackers with peanut 

butter, or veggies with hummus.

For more on healthy eating, read our brochure Better

Health and You: Tips for Adults. (See the Resources 

section for links to this and other WIN publications.)

Myth: Eating healthy food costs too much.

Fact: Eating better does not have to cost a lot of 

money. Many people think that fresh foods are 

healthier than canned or frozen ones. For example, 

some people think that spinach is better for you raw 

than frozen or canned. However, canned or frozen 

fruits and veggies provide as many nutrients as fresh 

ones, at a lower cost. Healthy options include lowsalt canned veggies and fruit canned in its own juice 

or water-packed. Remember to rinse canned veggies 

to remove excess salt. Also, some canned seafood, 

like tuna, is easy to keep on the shelf, healthy, and 

low-cost. And canned, dried, or frozen beans, lentils, 

and peas are also healthy sources of protein that are 

easy on the wallet.

TIP: Check the nutrition facts on canned, dried, 

and frozen items. Look for items that are high in 

calcium, fiber, potassium, protein, and vitamin D. 

Also check for items that are low in added sugars, 

saturated fat, and sodium. For more tips, see 

Smart Shopping for Veggies and Fruits and 

Healthy Eating on a Budget, both on the MyPlate 

website (see the Resources section).
5

Physical Activity Myths

Myth: Lifting weights is not a good way to lose 

weight because it will make me “bulk up.”

Fact: Lifting weights or doing activities like 

push-ups and crunches on a regular basis can help 

you build strong muscles, which can help you burn 

more calories. To strengthen muscles, you can lift 

weights, use large rubber bands (resistance bands), 

do push-ups or sit-ups, or do household or yard 

tasks that make you lift or dig. Doing strengthening 

activities 2 or 3 days a week will not “bulk you up.” 

Only intense strength training, along with certain 

genetics, can build large muscles. 

TIP: Government guidelines for physical activity 

recommend that adults should do activities at 

least 2 times a week to strengthen muscles. The 

guidelines also suggest that adults should get 

150 to 300 minutes of moderately intense or 

vigorous aerobic activity each week—like brisk 

walking or biking. Aerobic activity makes you 

sweat and breathe faster.

For more on the benefits of physical activity and 

tips on how to be more active, check out the 

Government’s guidelines for physical activity (see 

the Resources section for a link).

Myth: Physical activity only counts if I can do it 

for long periods of time.

Fact: You do not need to be active for long periods 

to achieve your 150 to 300 minutes of activity each 

week. Experts advise doing aerobic activity for periods 

of 10 minutes or longer at a time. You can spread 

these sessions out over the week.

TIP: Plan to do at least 10 minutes of physical 

activity three times a day on 5 or more days a 

week. This will help you meet the 150-minute 

goal. While at work, take a brief walking break. 

Use the stairs. Get off the bus one stop early. Go 

dancing with friends. Whether for a short or long 

period, bursts of activity may add up to the total 

amount of physical activity you need each week.

Don’t just sit there!

Americans spend a lot of time sitting in front 

of computers, desks, hand-held devices, and 

TVs. Break up your day by moving around more 

and getting regular aerobic activity that makes 

you sweat and breathe faster.

 Get 150 to 300 minutes of moderately 

intense or vigorous physical activity each 

week. Basketball, brisk walks, hikes, hula 

hoops, runs, soccer, tennis—choose whatever 

you enjoy best! Even 10 minutes of activity 

at a time can add up over the week.

 Strengthen your muscles at least twice a 

week. Do push-ups or pull-ups, lift weights, 

do heavy gardening, or work with rubber 

resistance bands.
6

Food Myths

Myth: Eating meat is bad for my health and 

makes it harder to lose weight.

Fact: Eating lean meat in small amounts can be 

part of a healthy plan to lose weight. Chicken, fish, 

pork, and red meat contain some cholesterol and 

saturated fat. But they also contain healthy nutrients 

like iron, protein, and zinc.

TIP: Choose cuts of meat that are lower in fat, 

and trim off all the fat you can see. Meats that 

are lower in fat include chicken breast, pork loin 

and beef round steak, flank steak, and extra lean 

ground beef. Also, watch portion size. Try to eat 

meat or poultry in portions of 3 ounces or less. 

Three ounces is about the size of a deck of cards.

Myth: Dairy products are fattening and 

unhealthy.

Fact: Fat-free and low-fat cheese, milk, and yogurt 

are just as healthy as whole-milk dairy products, 

and they are lower in fat and calories. Dairy products 

offer protein to build muscles and help organs work 

well, and calcium to strengthen bones. Most milk 

and some yogurts have extra vitamin D added to 

help your body use calcium. Most Americans don’t 

get enough calcium and vitamin D. Dairy is an 

easy way to get more of these nutrients.

TIP: Based on Government guidelines, you 

should try to have 3 cups a day of fat-free or 

low-fat milk or milk products. This can include 

soy beverages fortified with vitamins. If you can’t 

digest lactose (the sugar found in dairy products), 

choose lactose-free or low-lactose dairy products 

or other foods and drinks that have calcium and 

vitamin D: 

 Calcium: soy-based drinks or tofu made with 

calcium sulfate; canned salmon; dark leafy 

greens like collards or kale

 Vitamin D: cereals or soy-based drinks 

More questions?

If you do not know whether or not to believe a 

weight-loss or nutrition claim, check it out! The 

Federal Trade Commission has information on 

false weight-loss claims in ads. 

You can also find out more about nutrition 

and weight loss by talking with a registered 

dietitian through the Academy of Nutrition and 

Dietetics. See the Resources section for links.

Myth: “Going vegetarian” will help me lose 

weight and be healthier.

Fact: Research shows that people who follow a 

vegetarian eating plan, on average, eat fewer calories 

and less fat than non-vegetarians. Some research 

has found that vegetarian-style eating patterns 

are associated with lower levels of obesity, lower 

blood pressure, and a reduced risk of heart disease. 

Vegetarians also tend to have lower body mass index 

(BMI) scores than people with other eating plans. 

(The BMI measures body fat based on a person’s 

height in relation to weight). But vegetarians—like 

others—can make food choices that impact weight 

gain, like eating large amounts of foods that are high 

in fat or calories or low in nutrients. 
7

The types of vegetarian diets eaten in the United 

States can vary widely. Vegans do not consume any 

animal products, while lacto-ovo vegetarians eat milk 

and eggs along with plant foods. Some people have 

eating patterns that are mainly vegetarian but may 

include small amounts of meat, poultry, or seafood.

TIP: If you choose to follow a vegetarian eating 

plan, be sure you get enough of the nutrients that 

others usually take in from animal products like 

cheese, eggs, meat, and milk. Nutrients that may 

be lacking in a vegetarian diet are listed in the 

sidebar, along with foods and drinks that may help 

you meet your body’s needs for these nutrients.

Nutrient Common Sources

Calcium dairy products, soy drinks with added 

calcium, tofu made with calcium sulfate, 

collard greens, kale, broccoli

Iron cashews, spinach, lentils, chickpeas, 

bread or cereal with added iron

Protein eggs, dairy products, beans, peas, nuts, 

seeds, tofu, tempeh, soy-based burgers

Vitamin B12 eggs, dairy products, fortified cereal or 

soy drinks, tempeh, miso (tempeh and 

miso are foods made from soybeans)

Vitamin D foods and drinks with added vitamin D, 

including milk, soy drinks, or cereal

Zinc whole grains (check the ingredients list 

on product labels for the words “whole” 

or “whole grain” before the grain 

ingredient’s name), nuts, tofu, leafy 

greens (spinach, cabbage, lettuce)

Research

The National Institute of Diabetes and Digestive 

and Kidney Diseases (NIDDK) conducts and 

supports a broad range of basic and clinical obesity 

research. More information about obesity research 

is available at http://www.obesityresearch.nih.gov. 

Participants in clinical trials can play a more 

active role in their own health care, gain access to 

new research treatments before they are widely 

available, and help others by contributing to 

medical research. For more information, visit 

http://www.clinicaltrials.gov. 
8

Resources

Additional Reading from the Weight-control Information Network

The following materials are available from WIN at the phone and fax numbers and 

website listed in the sidebar under the WIN contact information.

■ Better Health and You: Tips for Adults helps adults plan steps toward eating healthier 

foods and being more physically active. 

■ Changing Your Habits: Steps to Better Health guides readers through steps that can 

help them determine what “stage” they are in—how ready they are—to make healthy 

lifestyle changes. The fact sheet also offers strategies on how to make healthy eating 

and physical activity changes. 

■ Choosing a Safe and Successful Weight-loss Program provides a list of things to 

look for when choosing a safe and effective weight-loss program, as well as a list of 

questions to ask program providers.

■ Tips to Help You Get Active offers ideas to beat some of the environmental, healthrelated, and personal roadblocks to making physical activity a part of one’s regular 

routine. 

■ Weight Loss for Life discusses the benefits of weight loss and ways to develop healthy 

eating and physical activity plans. In addition, the differences between the two types of 

formal weight-loss programs—clinical and nonclinical—are discussed.

Additional Resources

■ 2008 Physical Activity Guidelines for Americans. These guidelines provide general 

information on physical activity, including how often you should be active and which 

activities are best for you. Visit http://www.health.gov/PAGuidelines. 

■ Academy of Nutrition and Dietetics. To find a registered dietitian in your area, visit 

http://www.eatright.org or call 1–800–877–1600. 

■ Dietary Guidelines for Americans, 2010. You can find information and tips on healthy 

eating, shopping, and cooking online at http://www.health.gov/dietaryguidelines.

■ Federal Trade Commission. Check out weight-loss claims in ads at http://www.ftc.gov

or call 1–877–FTC–HELP (1–877–382–4357).

■ Healthy Eating on a Budget. 

http://www.choosemyplate.gov/healthy-eating-on-budget.html

■ How to Understand and Use the Nutrition Facts Label. This overview on the 

U.S. Food and Drug Administration’s website guides you in using the label to 

select healthy food for yourself and your family. Visit http://www.fda.gov/Food/

IngredientsPackagingLabeling/LabelingNutrition/ucm274593.htm.

■ MyPlate. Information, tips, and interactive tools about healthy eating and physical 

activity, as well as healthy eating on a budget, are available from the U.S. Department of 

Agriculture. Visit the MyPlate website at http://www.choosemyplate.gov. 

■ Smart Shopping for Veggies and Fruits. http://www.choosemyplate.gov/food-groups/

downloads/TenTips/DGTipsheet9SmartShopping.pdf

Weight-control 

Information Network

1 WIN Way

Bethesda, MD 20892–3665

Phone: 202–828–1025

Toll-free number: 1–877–946–4627

FAX: 202–828–1028

Email: WIN@info.niddk.nih.gov

Internet: http://www.win.niddk.nih.gov

http://www.facebook.com/win.niddk.nih.gov

The Weight-control Information Network 

(WIN) is a national information service 

of the National Institute of Diabetes and 

Digestive and Kidney Diseases (NIDDK), 

part of the National Institutes of Health 

(NIH). WIN provides the general public, 

health professionals, and the media with 

science-based, up-to-date, culturally 

relevant materials and tips. Topics include 

healthy eating, barriers to physical activity, 

portion control, and eating and physical 

activity myths. 

Publications produced by WIN are 

reviewed by both NIDDK scientists and 

outside experts. This fact sheet was also 

reviewed by Barbi Moore, R.D., L.D., 

Jefferson County Department of Health, 

South Birmingham, AL.

Inclusion of resources is for information 

only and does not imply endorsement by 

NIDDK or WIN.

This publication is not copyrighted. WIN 

encourages you to copy and share as many 

copies as desired.

Photo, page 4:

http://www.SweetOnVeg.com

Photo, page 5: 

Centers for Disease Control and 

Prevention (CDC)/Amanda Mills

Photo, page 7:

CDC/Cade Martin & Dawn Arlotta

This fact sheet is also available at 

http://www.win.niddk.nih.gov. 

NIH Publication No. 04–4561

March 2009

Updated November 2012

NIH...Turning Discovery Into Health®