Weight-loss and

Nutrition Myths

How Much Do You Really Know?

National Institute of Diabetes and

Digestive and Kidney Diseases

NATIONAL INSTITUTES OF HEALTH

WIN Weight-control Information Network

Diet Myths

Myth: Fad diets work for permanent weight loss.

Fact: Fad diets are not the best way to lose weight and keep it off.

Fad diets often promise quick weight loss or tell you to cut certain

foods out of your diet. You may lose weight at first on one of these

diets. But diets that strictly limit calories or food choices are hard to

follow. Most people quickly get tired of them and regain any lost

weight.

Fad diets may be unhealthy because they may not provide all of the

nutrients your body needs. Also, losing weight at a very rapid rate

(more than 3 pounds a week after the first couple weeks) may increase

your risk for developing gallstones (clusters of solid material in the

gallbladder that can be painful). Diets that provide less than 800

calories per day also could result in heart rhythm abnormalities,

which can be fatal.

Tip: Research suggests that losing 1⁄2 to 2 pounds a week by making

healthy food choices, eating moderate portions, and building physical

activity into your daily life is the best way to lose weight and keep it

off. By adopting healthy eating and physical activity habits, you may

also lower your risk for developing type 2 diabetes, heart disease, and

high blood pressure.

Myth: High-protein/low-carbohydrate diets are a

healthy way to lose weight.

Fact: The long-term health effects of a high-protein/lowcarbohydrate diet are unknown. But getting most of your daily calories

from high-protein foods like meat, eggs, and cheese is not a balanced

eating plan. You may be eating too much fat and cholesterol, which

may raise heart disease risk. You may be eating too few fruits,

“Lose 30 pounds

in 30 days!”

“Eat as much as you

want and still lose

weight!”

“Try the thigh buster

and lose inches fast!”

And so on, and so on. With so

many products and

weight-loss theories out

there, it is easy to get

confused.

The information in this fact

sheet may help clear up

confusion about weight loss,

nutrition, and physical

activity. It may also help you

make healthy changes in

your eating and physical

activity habits. If you have

questions not answered here,

or if you want to lose weight,

talk to your health care

provider. A registered dietitian

or other qualified health

professional can give you

advice on how to follow a

healthy eating plan, lose

weight safely, and keep it off.
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vegetables, and whole grains, which may lead to

constipation due to lack of dietary fiber. Following a

high-protein/low-carbohydrate diet may also make you

feel nauseous, tired, and weak.

Eating fewer than 130 grams of carbohydrate a day can

lead to the buildup of ketones (partially broken-down

fats) in your blood. A buildup of ketones in your blood

(called ketosis) can cause your body to produce high

levels of uric acid, which is a risk factor for gout (a

painful swelling of the joints) and kidney stones.

Ketosis may be especially risky for pregnant women

and people with diabetes or kidney disease.

Tip: High-protein/low-carbohydrate diets are often

low in calories because food choices are strictly

limited, so they may cause short-term weight loss.

But a reduced-calorie eating plan that includes

recommended amounts of carbohydrate, protein, and

fat will also allow you to lose weight. By following a

balanced eating plan, you will not have to stop eating

whole classes of foods, such as whole grains, fruits,

and vegetables—and miss the key nutrients they

contain. You may also find it easier to stick with a

diet or eating plan that includes a greater variety of

foods.

Myth: Starches are fattening and should

be limited when trying to lose weight.

Fact: Many foods high in starch, like bread, rice,

pasta, cereals, beans, fruits, and some vegetables (like

potatoes and yams) are low in fat and calories. They

become high in fat and calories when eaten in large

portion sizes or when covered with high-fat toppings

like butter, sour cream, or mayonnaise. Foods high in

starch (also called complex carbohydrates) are an

important source of energy for your body.

Tip: The Dietary Guidelines for Americans

recommends eating 6 to 11 servings a day,

depending on your calorie needs, from the bread,

cereal, rice, and pasta group—even when trying to

lose weight. Pay attention to your serving sizes—

one serving is equal to 1 slice of bread, 1 ounce of

ready-to-eat cereal, or 1⁄2 cup of pasta, rice, or cooked

cereal. Try to avoid high-fat toppings and choose

whole grains, like whole wheat bread, brown rice,

oatmeal, and bran cereal. Choose other starchy foods

that are high in dietary fiber too, like beans, peas,

and vegetables.

Myth: Certain foods, like grapefruit,

celery, or cabbage soup, can burn fat

and make you lose weight.

Fact: No foods can burn fat. Some foods with

caffeine may speed up your metabolism (the way your

body uses energy, or calories) for a short time, but they

do not cause weight loss.

Tip: The best way to lose weight is to cut back on

the number of calories you eat and be more

physically active.

Myth: Natural or herbal weight-loss

products are safe and effective.

Fact: A weight-loss product that claims to be

“natural” or “herbal” is not necessarily safe. These

products are not usually scientifically tested to prove

that they are safe or that they work. For example,

herbal products containing ephedra (now banned by

the U.S. Government) have caused serious health

problems and even death. Newer products that claim to

be ephedra-free are not necessarily danger-free,

because they may contain ingredients similar to

ephedra.

Tip:Talk with your health care provider before using

any weight-loss product. Some natural or herbal

weight-loss products can be harmful.
3

Meal Myths

Myth: “I can lose weight while eating

whatever I want.”

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

than you eat. It is possible to eat any kind of food you

want and lose weight. You need to limit the number of

calories you eat every day and/or increase your daily

physical activity. Portion control is the key. Try eating

smaller amounts of food and choosing foods that are

low in calories.

Tip: When trying to lose weight, you can still eat

your favorite foods—as long as you pay attention to

the total number of calories that you eat.

Myth: Low-fat or nonfat means no

calories.

Fact: A low-fat or nonfat food is often lower in

calories than the same size portion of the full-fat

product. But many processed low-fat or nonfat foods

have just as many calories as the full-fat version of the

same food—or even more calories. They may contain

added sugar, flour, or starch thickeners to improve

flavor and texture after fat is removed. These

ingredients add calories.

Tip: Read the Nutrition Facts Label 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. For more information

about reading food labels, read the brochure Energize

Yourself and Your Family, from the Weight-control

Information Network (WIN) or visit the U.S. Food

and Drug Administration (FDA) online at

www.cfsan.fda.gov/~dms/foodlab.html.

Myth: Fast foods are always an

unhealthy choice and you should not eat

them when dieting.

Fact: Fast foods can be part of a healthy weight-loss

program with a little bit of know-how.

Tip: Avoid supersize combo meals, or split one with

a friend. Sip on water or nonfat milk instead of soda.

Choose salads and grilled foods, like a grilled chicken

breast sandwich or small hamburger. Try a “fresco”

taco (with salsa instead of cheese or sauce) at taco

stands. Fried foods, like French fries and fried

chicken, are high in fat and calories, so order them

only once in a while, order a small portion, or split

an order with a friend. Also, use only small amounts

of high-fat, high-calorie toppings, like regular

mayonnaise, salad dressings, bacon, and cheese.

Myth: Skipping meals is a good way to

lose weight.

Fact: Studies show that people who skip breakfast

and eat fewer times during the day tend to be heavier

than people who eat a healthy breakfast and eat four or

five times a day. This may be because people who skip

meals tend to feel hungrier later on, and eat more than

they normally would. It may also be that eating many

small meals throughout the day helps people control

their appetites.

Tip: Eat small meals throughout the day that include

a variety of healthy, low-fat, low-calorie foods. For

more information about healthy eating, read the WIN

brochure Healthy Eating and Physical Activity Across

Your Lifespan: Tips for Adults.

Myth: Eating after 8 p.m. causes weight

gain.

Fact: It does not matter what time of day you eat. It

is what and how much you eat and how much physical

activity you do during the whole day that determines

whether you gain, lose, or maintain your weight. No

matter when you eat, your body will store extra

calories as fat.

Tip: If you want to have a snack before bedtime,

think first about how many calories you have eaten

that day. And try to avoid snacking in front of the TV

at night—it may be easier to overeat when you are

distracted by the television.
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Physical Activity Myth

Myth: Lifting weights is not good to do if

you want to lose weight, because it will

make you “bulk up.”

Fact: Lifting weights or doing strengthening

activities like push-ups and crunches on a regular basis

can actually help you maintain or lose weight. These

activities can help you build muscle, and muscle burns

more calories than body fat. So if you have more

muscle, you burn more calories—even sitting still.

Doing strengthening activities 2 or 3 days a week will

not “bulk you up.” Only intense strength training,

combined with a certain genetic background, can build

very large muscles.

Food Myths

Myth: Nuts are fattening and you should

not eat them if you want to lose weight.

Fact: In small amounts, nuts can be part of a healthy

weight-loss program. Nuts are high in calories and fat.

However, most nuts contain healthy fats that do not

clog arteries. Nuts are also good sources of protein,

dietary fiber, and minerals including magnesium and

copper.

Tip: Enjoy small portions of nuts. One-third cup of

mixed nuts has about 270 calories.

Myth: Eating red meat is bad for your

health and makes it harder to lose

weight.

Fact: Eating lean meat in small amounts can be part

of a healthy weight-loss plan. Red meat, pork, chicken,

and fish contain some cholesterol and saturated fat (the

least healthy kind of fat). They also contain healthy

nutrients like protein, iron, and zinc.

Tip: Choose cuts of meat that are lower in fat and

trim all visible fat. Lower fat meats include pork

tenderloin and beef round steak, tenderloin, sirloin

tip, flank steak, and extra lean ground beef. Also,

pay attention to portion size. One serving is 2 to 3

ounces of cooked meat—about the size of a deck of

cards.

Myth: Dairy products are fattening and

unhealthy.

Fact: Low-fat and nonfat milk, yogurt, and cheese

are just as nutritious as whole milk dairy products, but

they are lower in fat and calories. Dairy products have

many nutrients your body needs. They offer protein to

build muscles and help organs work properly, and

calcium to strengthen bones. Most milks and some

yogurts are fortified with vitamin D to help your body

use calcium.

Tip: In addition to doing at least 30 minutes of

moderate-intensity physical activity (like walking 2

miles in 30 minutes) on most days of the week, try

to do strengthening activities 2 to 3 days a week.

You can lift weights, use large rubber bands

(resistance bands), do push-ups or sit-ups, or do

household or garden tasks that make you lift or dig.
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Tip: The Dietary Guidelines for Americans

recommend that people aged 9 to 18 and over age

50 have three servings of milk, yogurt, and cheese a

day. Adults aged 19 to 49 need two servings a day,

even when trying to lose weight. A serving is equal

to 1 cup of milk or yogurt, 11⁄2 ounces of natural

cheese such as cheddar, or 2 ounces of processed

cheese such as American. Choose low-fat or nonfat

dairy products including milk, yogurt, cheese, and

ice cream.

 If you cannot digest lactose (the sugar found in dairy

products), choose low-lactose or lactose-free dairy

products, or other foods and beverages that offer

calcium and vitamin D (listed below).

Calcium: fortified fruit juice, soy-based beverage,

or tofu made with calcium sulfate; canned salmon;

dark leafy greens like collards or kale

Vitamin D: fortified fruit juice, soy-based

beverage, or cereal (getting some sunlight on your

skin also gives you a small amount of vitamin D).

Myth: “Going vegetarian” means you are

sure to 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. They also tend to

have lower body weights relative to their heights than

non-vegetarians. Choosing a vegetarian eating plan

with a low fat content may be helpful for weight loss.

But vegetarians—like non-vegetarians—can make

food choices that contribute to weight gain, like eating

large amounts of high-fat, high-calorie foods or foods

with little or no nutritional value.

Vegetarian diets should be as carefully planned as

non-vegetarian diets to make sure they are balanced.

Nutrients that non-vegetarians normally get from

animal products, but that are not always found in a

vegetarian eating plan, are iron, calcium, vitamin D,

vitamin B12, zinc, and protein.

Tip: Choose a vegetarian eating plan that is low in

fat and that provides all of the nutrients your body

needs. Food and beverage sources of nutrients that

may be lacking in a vegetarian diet are listed below.

Iron: cashews, spinach, lentils, garbanzo beans,

fortified bread or cereal

Calcium: dairy products, fortified soy-based

beverages or fruit juices, tofu made with calcium

sulfate, collard greens, kale, broccoli

Vitamin D: fortified foods and beverages including

milk, soy-based beverages, fruit juices, or cereal

Vitamin B12: eggs, dairy products, fortified cereal

or soy-based beverages, tempeh, miso (tempeh

and miso are foods made from soybeans)

Zinc: whole grains (especially the germ and bran

of the grain), nuts, tofu, leafy vegetables (spinach,

cabbage, lettuce)

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

seeds, tofu, tempeh, soy-based burgers.

If you don’t know whether or

not to believe a weight-loss or

nutrition claim, check it out!

The Federal Trade

Commission (www.ftc.gov/

bcp/conline/features/

wgtloss.htm) has information

on deceptive weight-loss

advertising claims. You can

also find out more about

nutrition and weight loss by talking with a registered

dietitian. To find a registered dietitian in your area,

visit the American Dietetic Association

(www.eatright.org/Public/

PublicDietitianDisclaimerAdvanced.htm) online or

call 1-800-877-1600.
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

National Institutes of Health

NIH Publication No. 04-4561

March 2004

Weight-control

Information

Network

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Internet: www.niddk.nih.gov/

health/nutrit/nutrit.htm

The Weight-control Information

Network (WIN) is a service of the

National Institute of Diabetes and

Digestive and Kidney Diseases

of the National Institutes of Health,

which is the Federal Government’s

lead agency responsible for

biomedical research on nutrition and

obesity. Authorized by Congress

(Public Law 103-43), WIN provides

the general public, health

professionals, the media, and

Congress with up-to-date, sciencebased health information on weight

control, obesity, physical activity,

and related nutritional issues.

WIN answers inquiries, develops and

distributes publications, and works

closely with professional and patient

organizations and Government

agencies to coordinate resources

about weight control and related

issues.

Publications produced by WIN are

reviewed by both NIDDK scientists

and outside experts. This fact sheet

was also reviewed by Donna Ryan,

M.D., F.A.C.P., Associate Executive

Director for Clinical Research,

Pennington Biomedical Research

Center.

This publication is not copyrighted. WIN

encourages users of this fact sheet to duplicate

and distribute as many copies as desired.

This fact sheet is also available at

www.niddk.nih.gov/health/nutrit/nutrit.htm.