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.
No Shortcuts To Losing
Weight
"There are no shortcuts--no magic
pills," says Lori Love, M.D., Ph.D., 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.
The first step in losing weight safely is to determine a realistic
weight goal. The table, at right, developed by the U.S. Department of
Agriculture and the Department of Health and Human Services, offers a
range of suggested weights for adults based on their height.
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).
Moderation, Variety and Balance
After determining a reasonable goal weight, devise an eating plan based
on the cornerstones of healthful eating--moderation, variety and
balance, suggests 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.
"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."
Using the Food Label
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.
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.
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.
Camille Brewer, a registered dietitian and nutritionist in FDA's Office
of Food Labeling, advises caution, however, when choosing foods that are
labeled "fat-free" and "low-fat." Some of these foods, like "low-fat"
cakes and cookies, still may be high in calories because of added
sugars. So dieters should always check the Nutrition Facts panel to get
complete information, she says.
Look for 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.
To see how the new label can help you stick to your diet, see Dieters'
Label Checklist (a 119K PDF file)
Exercise
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.
Diet Pills
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.
Rx Drugs
FDA has approved several prescription drugs for obesity. Those available
on the market include:
Dexedrine and other amphetamines
Ionamin and Adipex-P (phentermine), Sanorex (mazindol), Tenuate
(diethylpropion), Prelu-2 (phendimetrazine) and other amphetamine
derivatives
meridia (sibutramine).
In mostly short-term studies of obese adults following a
calorie-restricted diet, those who took the appetite suppressants lost
more weight on average than those who took a placebo. The amount of
weight lost varied from study to study.
FDA approved the drugs only for use with calorie-restricted diets. The
drugs are "not magic pills," warns Leo Lutwak, M.D., Ph.D., of FDA's
division of metabolism and endocrine drug products. "They don't work
unless you make dietary and exercise changes."
Also, they should be used only for a few weeks because the drugs are
addictive and have the potential for abuse. They shouldn't be used in
combination with each other or with other drugs for appetite control
because such combinations have not been evaluated for safety. And the
drugs should be used only in people who are obese--not people looking to
lose a few pounds, Lutwak says.
"Weight-loss drugs are serious medicine for a serious disease," he says.
Also, he points out that while obesity may be associated with other
serious diseases, studies have never shown that weight loss produced
with the use of prescription weight-loss drugs benefits
obesity-associated conditions. However, changes in diet and activity may
improve associated diseases, such as diabetes and high blood pressure,
even with only modest changes in weight, Lutwak says.
Until September 1997, two other drugs, fenfluramine (Pondimin and
others) and dexfenfluramine (Redux), were available for treating
obesity. But, at FDA's request, the manufacturers of these drugs
voluntarily withdrew them from the market after newer findings suggested
that they were the likely cause of heart valve problems in a large
proportion of people using them. FDA recommended that anyone taking the
drugs stop and that they contact their doctor to discuss their
treatment. (For the latest information on this topic, visit
www.fda.gov/cder/news/feninfo.htm on FDA's Website.)
Weight-Loss Programs
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. n
Marilynn Larkin is a writer in New York City. Paula Kurtzweil, a member
of FDA's public affairs staff, also contributed to this article.
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