Modified Fast: Overweight Problem

by Food and Drug Administration (FDA)

Overweight is a hefty problem in the United States. It's estimated that 24 percent of men and 27 percent of women in this country about 34 million adult Americans are obese. And sometimes it seems that there are 34 million different diets or diet products promoted to combat the problem. The latest to win the nation's fervent attention is a revival of a sort return to very low calorie diets, generally 400 to 800 calories per day.

Very low calorie, or modified fasting, diets, as they are sometimes called, are not a new concept. Protein formula products (either liquid or powdered) were popular more than a decade ago until serious health effects including several deaths dampened the public's enthusiasm and led to new federal requirements for labeling of these products

New Product, New Program

The modified fast regimen is enjoying renewed popularity, but today's very low calorie diet products differ markedly in both content and use from those of the past. While many of the formulas of the 70s were directly available to consumers through supermarkets and other retail outlets, the newer products are sold only to doctors or hospitals for use in medically supervised programs that include frequent medical examinations and behavior modification training.

Some dieters using the old products subsisted on as few as 300 calories per day of a nutritionally deficient product consisting primarily of a poor-quality protein (usually a hydrolyzed gelatin). Unlike the old diet formulas, today's Optifast, Medifast, HMR, and similar products contain a high-quality protein (egg white- or milk-based), carbohydrates, and some fat and are supplemented to meet recommended dietary allowances for vitamins, minerals and electrolytes. They are not a panacea, however, and, as the American Dietetic Association recently warned, they are not for everyone.

The comeback of very low calorie diets had been fairly quiet until last winter, when they were catapulted into the limelight by talk show host Oprah Winfrey. With some flair, Winfrey demonstrated on national television how she won the battle of the bulge with Optifast. Carting 67 pounds of animal fat on the television set to dramatize how much extra weight she had been carting around in her body pre-Optifast, Winfrey made quite an impact on her viewers and many more of the nation's dieters who learned about her transformation from newspapers, magazines, television, and radio.

That Lean and Healthy Look

Shedding that 67 pounds not only took inches from Winfrey's torso, it may add years to her life as well. For the problem of obesity is not simply a matter of whether a ?slim, svelte look is or is not more appealing than one that's pleasingly plump. Observations from the famous Framingham Heart Study, in which several thousand members of the small Massachusetts town have been followed medically since 1948, have shown that a 20 percent excess over ideal weight constitutes a health risk.

Overweight has been linked to a long list of health problems high blood pressure, respiratory problems, nighttime sleeplessness and (resulting daytime sleepiness), heart disease, diabetes mellitus, elevated blood lipids, gallstones, arthritis, and some cancers including that of the breast, endometrium and gallbladder in women, and colon, rectum and prostate in men.

Like Winfrey, Karen, who asked that her real name not be used, has been battling the bulge for years. A 41-year-old registered nurse, Karen has been on one diet or another almost continuously since she was 15 years old, losing and regaining pounds for 26 years.

The Program

And, like Winfrey, Karen lost 67 pounds on Optifast. Hers was a 20-week program that consisted of 12 weeks of fasting, six weeks of refeeding, and two weeks of maintenance. During the fasting phase, Karen subsisted on five packets a day of an 85-calorie powder formula reconstituted with water or a very low calorie diet beverage with no sodium or caffeine. She also took a potassium supplement daily. (An 800-calorie diet is prescribed for some people for example, for medical reasons or for very active overweight men who require more calories to get through the day.) Solid food was gradually introduced over the next six weeks, and the final two weeks were devoted to maintaining weight. Karen had blood tests done every other week throughout the program to check sodium, potassium, and other blood chemistries, and an electrocardiogram once a month to check for heart abnormalities.

Also integral to the program and mandatory was nutrition education and behavior modification training with a psychological component to help overeaters examine why they overeat and how they can replace their food dependency with other pleasurable activities, such as exercise, reading, or listening to music. The program has been modified slightly since Karen took it three years ago, but it and other medically supervised very low calorie diet programs remain similar in content, calories, recommended length of use, and cost.

A 67-pound weight loss in 20 weeks sounds pretty good, doesn't it. But before you lace up your running shoes to dash out and sign yourself up, consider the following the program may not be for you. To begin with, you may be screened out. You must be a certain amount overweight; in Karen's program, entry criteria are at least 50 pounds or 30 percent over ideal weight. People with a history of certain medical problems such as liver or kidney disease, heart failure, cancer or Type I (insulin-dependent) diabetes may not be accepted. Even if you qualify, when you learn the cost, you may want to screen yourself out the range is generally from $100 to $150 a week. This includes all aspects of the program the formula, supplements, medical exams, and behavior modification training.

And then there's the C word commitment. In a recent issue of the International Journal of Obesity, Marvin A. Kirschner, M.D., and his colleagues at Newark Beth Israel Medical Center, N.J., reported that of 4,026 morbidly obese patients (at least 100 pounds over ideal weight) who began the Optifast program, one-fourth dropped out within the first three weeks.

Results: Good and Bad

What about the 3,020 men and women who stuck it out? Sixty-eight percent lost considerable weight but did not reach their goal, and only 5 to 10 percent of them had maintained the weight loss after 18 months. The 32 percent who attained their goal by program's end proved to have greater staying power; 30 percent of the women and 58 percent of the men kept off the pounds for at least 18 months.

Kirschner and colleagues reported lightheadedness and tiredness as the most common complaints among dieters early on in the fast. The most common late complaint was a mild transient hair loss, experienced by about 10 percent of the participants. There were two cases of acute gout; two cases of foot drop, which the authors speculate were due to sciatic nerve compression from leg crossing during or after weight loss; and four cases of acute psychosis. One patient developed a rapid heartbeat due to low blood sugar, which was corrected with intravenous glucose, and two patients were hospitalized for irregular heartbeats.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.