Losing Weight Safely (FDA Consumer Reprint)

U.S. Food and Drug Administration
FDA Consumer magazine
January-February 1996
Table of Contents

This article originally appeared in the January-February 1996FDA Consumer. This article is no longer current. For current information on this topic, see Information about Losing Weight and Maintaining a Healthy Weight on this Website.

Losing Weight Safely

Americans trying to lose weight have plenty of company. According to a 1995 report from the Institute of Medicine (IOM), tens of millions of Americans are dieting at any given time, spending more than $33 billion yearly on weight-reduction products, such as diet foods and drinks.

Yet, studies over the last two decades by the National Center for Health Statistics show that obesity in the United States is actually on the rise. Today, approximately 35 percent of women and 31 percent of men age 20 and older are considered obese, up from approximately 30 percent and 25 percent, respectively, in 1980.

The words obesity and overweight are generally used interchangeably. However, according to the IOM report, their technical meanings are not identical. Overweight refers to an excess of body weight that includes all tissues, such as fat, bone and muscle. Obesity refers specifically to an excess of body fat. It is possible to be overweight without being obese, as in the case of a body builder who has a substantial amount of muscle mass. It is possible to be obese without being overweight, as in the case of a very sedentary person who is within the desirable weight range but who nevertheless has an excess of body fat. However, most overweight people are also obese and vice versa. Men with more than 25 percent and women with more than 30 percent body fat are considered obese.

Many people who diet fail to lose weight--or, if they do lose, fail to maintain the lower weight over the long term. As the IOM report, "Weighing The Options: Criteria for Evaluating Weight-Management Programs," points out, obesity is "a complex, multifactorial disease of appetite regulation and energy metabolism."

Because many factors affect how much or how little food a person eats and how that food is metabolized, or processed, by the body, losing weight is not simple. For example, recent studies suggest a role for genetic makeup in obesity. This area is still controversial, and more studies will be needed before scientists can say with certainty that a person's genes may set limits on how much weight can be lost and maintained.

Yet many people persist in seeking simple cures to this complex health problem. Lured by fad diets or pills that promise a quick and easy path to thinness, they end up disappointed when they regain lost weight.

"When it comes to weight loss, if something sounds too good--or too easy, or too delicious--to be true, it probably is," says Victor Herbert, M.D., J.D., professor of medicine and director of the Nutrition Center at the Mount Sinai School of Medicine and Bronx VA Medical Centers in New York City, and member of the board of directors of the National Council Against Health Fraud. "If a weight loss claim is sensational, it is not true; if it is true, it is not sensational."

"There are no shortcuts--no magic pills," adds Lori Love of the Food and Drug Administration's Center for Food Safety and Applied Nutrition. Losing weight sensibly and safely requires a multifaceted approach that includes setting reasonable weight-loss goals, changing eating habits, and getting adequate exercise. Appetite suppressants (diet pills) or other products may help some people over the short term, but they are not a substitute for adopting healthful eating habits over the long term.

A physician, dietitian or nutritionist also can help you set a reasonable goal. To reach the goal safely, plan to lose 1 to 2 pounds weekly by consuming approximately 300 to 500 fewer calories daily than usual (women and inactive men generally need to consume approximately 2,000 calories to maintain weight; men and very active women may consume up to 2,500 calories daily).

After determining a reasonable goal weight, devise an eating plan based on the cornerstones of healthful eating--moderation, variety and balance, suggests Herbert.

"Moderation means not eating too much or too little of any particular food or nutrient; variety means eating as wide a variety as possible from each, and within each, of the five basic food groups; and balance refers to the balance achieved by following moderation and variety, as well as the balance of calories consumed versus calories expended," he explains. To lose weight, fewer calories should be consumed than expended; to maintain weight loss, the number of calories consumed and expended should be about the same.

Because fat is the most concentrated source of calories (9 calories per gram compared to 4 calories per gram for carbohydrate and protein), it is usually the focus of weight-maintenance and weight-loss diets. Limiting fat intake alone will likely limit calories, as well. Just as for the general population, weight-conscious consumers should limit fat intake to no more than 30 percent of total calories, according to the Dietary Guidelines for Americans.

Alcoholic beverages also are a source of calories (7 per gram of alcohol). Twelve ounces of regular beer, for example, provides 150 calories; the same amount of "light" beer, 105 calories. Five ounces of wine or 1.5 ounces of 80-proof distilled spirits provide 100 calories. But alcohol provides few, if any, nutrients, so if you drink alcoholic beverages and want to reduce your weight, consider reducing or eliminating your alcohol intake.

In selecting your diet, follow the five basic food groups and the recommended number of servings from each as incorporated into the Food Guide Pyramid developed by USDA and HHS. These groups are (1) bread, cereal, pasta, and rice; (2) vegetables; (3) fruits; (4) milk, yogurt and cheese; and (5) meat, poultry, fish, dry beans, eggs, and nuts. A sixth group (fats, oils and sweets) consists mainly of items that are pleasing to the palate but high in fat and/or calories; these should be eaten in moderation.

Avoid low-calorie fad diets that exclude whole categories of food such as carbohydrates (bread and pasta) or proteins (meat and poultry). These diets may be harmful because they generally do not include all nutrients necessary for good health. "Every fad diet that demands an unusual eating pattern, such as emphasizing only a few types of foods, deviates from one or more of the guidelines of moderation, variety and balance," says Herbert. "The greater the deviation, the more harmful the diet is likely to be."

To help consumers plan a healthful diet, FDA and USDA have revamped food labels. By law, most food labels now must display a Nutrition Facts panel containing information about how the food can fit into an overall daily diet. Nutrition Facts state how much saturated fat, cholesterol, fiber, and certain nutrients are contained in each serving. Serving sizes must now be based on standards set for similar kinds of food, so the nutritional value of similar products may be compared.

On the food label, %Daily Value shows what percentage of a given nutrient is provided in one portion for daily diets of 2,000 calories.

Whether or not a given food fits into a weight-loss diet depends on what other foods you eat that day. For most people, the goal is to select a variety of foods that together add up to approximately 100 percent of the Daily Value for total carbohydrate, dietary fiber, vitamins, and minerals; total fat, cholesterol and sodium each may add up to less than 100 percent.

This system permits a good deal of flexibility. No food is inherently "bad"; it is the total diet for the day that counts. You may compensate for an occasional rich dessert or serving of fried food by eating foods that are low in fat, oil or sugar for the rest of the day. However, high-fat foods should be limited, because they can quickly use up a day's supply of calories without providing high percentages of vital nutrients.

Look on the nutrition label for words such as "low," "light" or "reduced" to describe the calorie and fat content per serving. These foods must have significantly fewer calories or significantly less fat than similar products that do not make these claims.

Foods that claim to contain fewer calories or less fat than similar servings of similar products must show the difference on the label. For example, on a container of low-fat cottage cheese, the label would show that a serving of the low-fat product contains 80 calories and 1.5 grams of fat while regular cottage cheese contains 120 calories and 5 grams of fat per serving.

Simple modifications in food selection and preparation allow you to include traditional favorites and snacks within the context of a healthful weight-loss diet; for example, select 1 percent or skim milk products instead of those made with whole milk, lean cuts of meat and poultry, and nonfat frozen yogurt instead of ice cream. Low-fat plain yogurt may be substituted for sour cream in dips, dressings or spreads; reduced-fat cheeses may be used instead of those made from whole milk. Broil, roast or steam foods instead of frying.

Load up on foods high in fiber, such as fruits, vegetables, legumes and whole grains. Fiber can be an important aid in weight maintenance because eating enough of it can help make a person feel full and thus not eat as much.

Also, include small portions of desserts or high-fat snacks rather than attempting to cut them out altogether. Eliminating favorite foods may result in cravings that can lead to binge eating and weight gain.

Regular exercise is important for overall health as well as for losing and maintaining weight. There is evidence to suggest that body fat distribution affects health risks. For example, excess fat in the abdominal area (as opposed to hips and thighs) is associated with greater risk for high blood pressure, diabetes, early heart disease, and certain types of cancer. Vigorous exercise can reduce abdominal fat and thus lower the risk of these diseases.

The Dietary Guidelines for Americans recommends a half hour or more of moderate physical activity on most days, preferably every day. The activity can include brisk walking, calisthenics, home care, gardening, moderate sports exercise, and dancing. Regular exercise can help the body use up calories consumed daily, as well as excess calories stored as fat. Weight-bearing exercises also help tone muscles and may reduce the risk of osteoporosis.

The 1991/1992 Weight Loss Practices Survey, sponsored by FDA and the National Heart, Lung, and Blood Institute, found that 5 percent of women and 2 percent of men trying to lose weight use diet pills. Products considered by FDA to be over-the-counter weight control drugs are primarily those containing the active ingredient phenylpropanolamine (PPA), such as Dexatrim and Acutrim. PPA is available OTC for weight control in a 75-mg controlled-release dosage form, when combined with a restricted diet and exercise.

Using diet pills containing PPA will not make a big difference in the rate of weight loss, says Robert Sherman of FDA's Office of OTC Drug Evaluation. "Even the best studies show only about a half pound greater weight loss per week using PPA combined with diet and exercise," he adds. Sherman cautions that the recommended dosage of these pills should not be exceeded because of the risk of possible adverse effects, such as elevated blood pressure and heart palpitations.

Since PPA is also used as a nasal decongestant in over-the-counter cough and cold products, consumers should read the labels of OTC decongestants to see if they contain PPA. They should not take PPA in two products labeled for different uses.

Sherman notes that FDA has received a small number of reports indicating that PPA use might be associated with an increased risk of stroke. A large-scale safety study was begun in September 1994 to explore the possibility. Based on available data, the agency does not believe that an increased risk of stroke is a concern when PPA is used at recommended dosages.

FDA has approved several prescription drugs for treating obesity. These include:

The drugs' potential to promote long-term maintenance of weight loss has not been demonstrated except in the case of dexfenfluramine, which has been found effective and safe for use up to one year.

The drugs are "not magic pills," Lutwak warns. "They don't work unless you make dietary and exercise changes." FDA approved the drugs only for use with calorie-restricted diets.

The drugs face other restrictions. Except for dexfenfluramine, they should be used only for a few weeks. Dexfenfluramine can be used up to one year. Data on its safety and effectiveness beyond one year is not available.

Also, these drugs should be used only in people who are obese--not people looking to lose a few pounds, Lutwak says.

One reason is that the drugs are addictive and have the potential for abuse. Another is that the drugs have serious side effects, including high blood pressure and sleep disturbances. Also, certain drugs are not advised for people with certain medical conditions, such as phentermine for people with heart disease or high blood pressure, and fenfluramine and dexfenfluramine for people taking certain anti-depressants.

Many people turn to weight-loss programs for help in planning a daily diet and changing lifestyle habits. The IOM report provides guidelines for evaluating the potential effectiveness of such programs.

"To improve their chances for success, consumers should choose programs that focus on long-term weight management; provide instruction in healthful eating, increasing activity, and improving self-esteem; and explain thoroughly the potential health risks from weight loss," according to the report. Consumers should also demand evidence of success. If it is absent or consists primarily of testimonials or other anecdotal evidence, "the program should be viewed with suspicion."

IOM recommends that potential clients be given a truthful, unambiguous, non-misleading statement about the program's approaches and goals, and a full disclosure of costs. The cost breakdown should include initial and ongoing costs, as well as the cost of extra products.

The basic tenet of weight loss--to eat fewer calories than you burn and to stay active--is easy to say but, like most lifestyle changes, not so easy to do. With realistic goals, and a commitment to losing weight slowly, safely and sensibly, the chances of long-term success improve dramatically.

Marilynn Larkin is a writer in New York City. Paula Kurtzweil, a member of FDA's public affairs staff, also contributed to this article.

Obesity a Disease

Public health concerns about this disease relate to its link to numerous other diseases that can lead to premature illness or death. The report notes that overweight individuals who lose even relatively small amounts of weight are likely to:

To order a copy of the IOM report, call (1-800) 624-6242 (in Washington, D.C., call 202-334-3313). The cost is $30 plus $4 shipping and handling.