Weight-loss and Nutrition Myths - How Much Do You Really Know

By the National Institute of Diabetes and Digestive and Kidney Disease. Use your browser's back button to navigate this diet menu

• Diet Myths
• Meal Myths
• Physical Activity Myth
• Food Myths

“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 will 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.

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 of 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 ½ 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/low-carbohydrate 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, 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: A healthy eating plan is one that:

Emphasizes fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products.
Includes lean meats, poultry, fish, beans, eggs, and nuts.
Is low in saturated fats, trans fat, cholesterol, salt (sodium), and added sugars.

For more specific information about food groups and nutrition values, visit www.healthierus.gov/dietaryguidelines.

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.

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Meal Myths

Photo of a bowl of cereal and milk

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 fat-free means no calories.

Fact: A low-fat or fat-free food is often lower in calories than the same size portion of the full-fat product. But many processed low-fat or fat-free 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 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, visit the U.S. Food and Drug Administration 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 fat-free 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 Weight-control Information Network 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.

Physical Activity Myth

Photo of a woman lifting hand weights

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.

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.

Food Myths

Photo of a woman eating a salad at home

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-half ounce 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. Three ounces of meat or poultry is the size of a deck of cards.

Myth: Dairy products are fattening and unhealthy.

Fact: Low-fat and fat-free 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: The 2005 Dietary Guidelines for Americans recommends consuming 3 cups per day of fat-free/low-fat milk or equivalent milk products. For more information on these guidelines, visit www.healthierus.gov/dietaryguidelines.

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: soy-based beverage or tofu made with calcium sulfate; canned salmon; dark leafy greens like collards or kale
  
• Vitamin D: 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 nonvegetarians. They also tend to have lower body weights relative to their heights than nonvegetarians. Choosing a vegetarian eating plan with a low fat content may be helpful for weight loss. But vegetarians—like nonvegetarians—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 nonvegetarian diets to make sure they are balanced. Nutrients that nonvegetarians 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, tofu made with calcium sulfate, collard greens, kale, broccoli
• Vitamin D: fortified foods and beverages including milk, soy-based beverages, 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 do not 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) online or call 1-800-877-1600.

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Weight-control Information Network

1 WIN Way
Bethesda, MD 20892-3665
Phone: (202) 828-1025
Toll-free phone: 1-877-946-4627
Fax: (202) 828-1028
Email: win@info.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) 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, science-based health information on weight control, obesity, physical activity, and related nutritional 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 e-text is not copyrighted. WIN encourages users of this fact sheet to duplicate and distribute as many copies as desired.

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March 2004
Updated August 2006

A Review of Popular Diets:
Dr. Phil's, Atkins, Zone, Raw Foods & Sugar Busters

By the time you read this, there may already be a new best-selling diet book heading the list, but with some help from current or former Americian Dietetic Association media spokespeople we have put together this fact sheet to give you.

Dr. Phil’s Ultimate Weight Solution - The Ultimate Weight Solution: The 7 Keys to Weight Loss Freedom

Ultimate Weight Solution: The 7 Keys to Weight Loss Freedom

And for adolescents… The Ultimate Weight Loss Solution for Teens: The 7 Keys to Weight Freedom

Ultimate Weight Solution for Teens: The 7 Keys to Weight Freedom

Written by Dr. Phil’s son, this book is essentially a gentler version of the original Ultimate Weight Solution. While I do like the way it adapts the 7 Keys for kids with softer, hopeful language, this diet is still comprised of recycled behavior modification tips and unrealistically simple solutions to treating obesity and eating disorders. —Lisa Dorfman, MS, RD, LMHC, Licensed Psychotherapist. By Jay McGraw, Free Press, 2003.

The “New” Atkins Diet Dr. Atkins' New Diet Revolution: Revised and Improved

Dr. Atkins' New Diet Revolution

Diet Summary Arguably one of the most famous fad diets, the Atkins Diet program restricts carbohydrates and focuses on eating mostly protein with the use of vitamin and mineral supplements. According to the program, this will alter a body’s metabolism so it will burn stored fat while building muscle mass. The “new” Atkins Diet is the same diet with a more liberal maintenance plan. With the “new” Atkins diet, some of the sensationalism is gone and there is heavy promoting of low-carb bars and food products from Atkins Nutritionals, Inc. But the bottom line is still the same. Carbs are demonized and there are major restrictions on fruits and vegetables, whole grains, legumes and low-fat dairy foods, which contradicts everything we know about health promotion and disease prevention. —Keith Ayoob, EdD, RD, FADA, By Robert C. Atkins, MD, Avon, 2001.

The Zone Diet The Zone: Revolutionary Life Plan to Put Your Body in Total Balance for Permanent Weight Loss

Week in the Zone: A Quick Course in the Healthiest Diet for You

Diet Summary Promoting a “balanced nutritional approach,” the Zone Diet is a complex eating plan that divides each meal into proportions of 40 percent carbohydrates, 30 percent proteins and 30 percent fats. The “Zone” refers to the state in which the body is at its physical peak, presumably from following this diet.

While the Zone Diet is closer to what most dietetics professionals would recommend compared to other fad diets, there are still better nutrition and exercise programs that are less complicated and frustrating than constantly measuring proportions and counting calories. —Althea Zanecosky, MS, RD By Barry Sears, MD, Regan Books, 1995.

South Beach Diet The South Beach Diet: The Delicious, Doctor-Designed, Foolproof Plan for Fast and Healthy Weight Loss

The South Beach Diet

Diet Summary Comprised of three phases, the South Beach Diet begins by banning carbohydrates such as fruit, bread, rice, potatoes, pasta and baked goods and allowing normal-size portions of meat, poultry, shellfish, vegetables, eggs and nuts. Dieters are told they will lose between eight and 13 pounds in the first two weeks during the “detoxification” phase. The second phase reintroduces “good carbs” (as defined using an online glycemic index) and dieters expect to lose one to two pounds per week until the weight goal is reached. The third phase is the least restrictive, allowing the dieters to eat pretty much anything in moderation. The theory behind the South Beach Diet is that the faster sugars and starches are digested, the more weight is gained. Instead, the diet will cause weight loss because it is a low-calorie plan with an average intake of about 1,400 to 1,500 calories per day. The diet’s first phase promotes potentially dangerous accelerated weight loss; however, the second and third phases emphasize whole grains, lean proteins and dairy, unsaturated fats and fruits and vegetables, in addition to consistent meal times, snacks, a healthy dessert and plenty of water. —Dawn Jackson, RD, LD By Arthur Agaston, MD, Rodale Press, 2003.

Raw Food Diets The Raw Life: Becoming Natural in an Unnatural World

The Raw Life: A Guide to the Raw Food Diet and Lifestyle: Becoming Natural in an Unnatural World

Diet Summary Various versions of raw food diets exist, but they share the same basic principle: Cooked foods lose the natural vitamins, nutrients and enzymes necessary to build a strong immune system. They recommend eating only fruits and vegetables picked ripe from the tree, garden or vine (organic preferred), nuts or seeds. Some raw food diets claim that it is “not natural” to eat sea vegetables, and others say that they are very important to include in the diet.

Raw food diets may be high in fiber and low in total fat, saturated fat, cholesterol and calories, but they restrict so many important foods that it becomes challenge to get all the nutrients the body needs. For example, avoiding all animal foods presents a challenge in getting enough vitamins B12 and D. —Claudia M. González, MS, RD, LD/N By Paul Nison, 343 Publishing Company, 2000, and Raw, the Uncooked Book by Juliano Brotman and Erika Lenkert, Regan Books, 1999

Sugar Busters The New Sugar Busters! Cut Sugar to Trim Fat

The New Sugar Busters! Cut Sugar to Trim Fat

Diet Summary The basic tenet of Sugar Busters is that all sugars, including the sugar derived from complex carbohydrates and starches, are “toxic” because they produce excess insulin, which causes our bodies to store sugar as fat and make cholesterol. According to the book, foods with a high glycemic index produce a greater insulin response and fat storage. The book concludes with a list of acceptable foods and foods to avoid, a 14-day sample meal plan, and Sugar Busters! recipes. The diet is recommended as appropriate for children, pregnant women, people with diabetes, hypoglycemia sufferers and persons with a history of cardiovascular disease.

The carbohydrate/insulin response theory as a cause of weight gain has become popular in fad diets, but there is no evidence that excess insulin release causes obesity in people with normal pancreatic function. Obesity is more likely a result of a decline in physical activity and increase in calorie intake than increased sugar or carbohydrate consumption. While the authors mention that protein foods and fats should also be limited, some of the recipes suggest the contrary, such as the filet mignon recipe for four that includes four 10-ounce filets, a cup of blue cheese and a half-pound of bacon. —Kathleen Zelman, MPH, RD, LD By H. Leighton Steward; Morrison C. Bethea, MD; Sam S. Andrews, MD; Luis A. Balart, MD, Ballatine Books, 1998.

Dieting and Weight Loss References

The North American Association for the Study of Obesity: http://www.obesityresearch.org/

The Healthy Weight Forum has some good information: http://www.healthyweightforum.org

You can find a TOPS (Take Off Pounds Sensibly) group in your area by searching by zip code on their website: http://www.tops.org/

Locate a Weight Watchers chapter on their website: http://www.weightwatchers.com

Recommended Reading for Dieting and Weight Loss

American Dietetic Association Complete Food and Nutrition Guide by Roberta Larson Duyff, MS, RD, FADA, CFCS, John Wiley & Sons 2002

?Dieting for Dummies, second edition by Jane Kirby, RD, Wiley Publishing, 2004

?The Way to Eat by David L. Katz, MD, MPH, FACPM and Maura H. Gonzalez, MS, RD, Sourcebooks, 2002

?365 Days of Healthy Eating from the American Dietetic Association by Roberta Larson Duyff, MS, RD, FADA, CFCS, John Wiley, 2004

?ADA Guide to Healthy Eating for Kids: How Your Children Can Eat Smart from 5 to 12 by Jodie Shield, MEd, RD and Mary Catherine Mullen, MS, RD, John Wiley, 2002

?ADA Guide to Eating Right When You Have Diabetes by Maggie Powers, MS, RD, CDE, John Wiley, 2003

?ADA Guide to Better Digestion by Leslie Bonci, MPH, RD, John Wiley, 2003.