15 Myths About Weight Loss, Nutrition, and Diet

Part 1 of 3 - Separating Diet Myths and Facts

young woman holding a pan with sautéed vegetables
Kathrin Ziegler/Taxi/Getty Images

Myth #1: 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 tire 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 few 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, or high blood pressure.

Myth #2: 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, or 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 #3: Starches are fattening and should be limited when trying to lose weight.

Fact: Many foods high in starch, are low in fat and calories such as:

  • bread
  • rice
  • pasta
  • cereals
  • beans
  • fruits
  • some vegetables (like potatoes and yams)

These foods become high in fat and calories when eaten in large portion sizes or when covered with high-fat toppings, such as 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 recommend 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 ½ cup of pasta, rice, or cooked cereal. Try to avoid high-fat toppings and choose whole grains, such as:

  • whole wheat bread
  • brown rice
  • oatmeal
  • bran cereal

Choose other starchy foods that are high in dietary fiber too: beans, peas, and vegetables.

Myth #4: 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 #5: 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 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.

Go on to Part 2 --- What You Can or Can't Eat When Dieting --->

Myth #6: You can't lose weight while eating your favorite foods.

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 #7: Low-fat or nonfat is synonymous with 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 as well. The serving size may be less than you are used to eating.

    Myth #8: 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, such as:

    • regular mayonnaise
    • salad dressings
    • bacon
    • cheese

    Myth #9: 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.

    Myth #10: 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 engage in 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.

    Also, try to avoid snacking in front of the TV at night since it may be easier to overeat when you are distracted by the television.

    Myth #11: Lifting weights is a bad idea 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 resistance bands
    • do push-ups or sit-ups
    • do household or garden tasks that make you lift or dig

    Myth #12: 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 a good source 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.

    Go on to Part 3 --- Making Optimal Dietary Choices --->

    Myth #13: 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
    • beef round steak
    • tenderloin
    • sirloin tip
    • flank steak
    • 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 #14: 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: 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, 1½ 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
    • 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.

    • Calcium: fortified fruit juice, soy-based beverage, or tofu made with calcium sulfate; canned salmon; dark leafy greens (e.g., 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 #15: "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, such as 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 obtain from animal products, but that are not always found in a vegetarian eating plan, include:

    • iron
    • calcium
    • vitamin D
    • vitamin B12
    • zinc
    • protein

    Tip: Choose a vegetarian eating plan that is low in fat and that provides all of the nutrients your body needs. 

    • 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 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.

    Source: NIH Publication No. 04-4561

    Go Back to Part 1 --- Separating Diet Myths and Facts --->

    Continue Reading