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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 treating obesity. These include:

• Dexedrine and other amphetamines
• Ionamin and Adipex-P (phentermine) and other amphetamine derivatives
• Pondimin (fenfluramine hydrochloride) and Redux (dexfenfluramine), drugs not related to amphetamines.

The drugs appear to accomplish the same thing: They seem to help people on calorie-restricted diets adhere more closely to their diet, says Leo Lutwak, M.D., Ph.D., of FDA's division of metabolism and endocrine drug products. In studies of people on calorie-restricted diets, those who took the drugs lost more weight on average than those who took a placebo. The amount of weight lost varied but tended to be a loss of a fraction of a pound more per week.

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.

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.

Obesity a Disease

Obesity is now considered a disease — not a moral failing. According to a new report from the Institute of Medicine, "obesity is a heterogeneous disease in which genetic, environmental, psychological, and other factors are involved. It occurs when energy intake exceeds the amount of energy expended over time. Only in a small minority of cases is obesity caused by such illnesses as hypothyroidism or the result of taking medications, such as steroids, that can cause weight gain."

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:

• lower their blood pressure (and thereby the risk of heart attack and stroke)
• reduce abnormally high levels of blood glucose (associated with diabetes)
• bring blood levels of cholesterol and triglycerides (associated with cardiovascular disease) down to more desirable levels
• reduce sleep apnea, or irregular breathing during sleep
• decrease the risk of osteoarthritis of the weight-bearing joints
• decrease depression
• increase self-esteem.

Of course, losing excess weight is also likely to improve appearance, which is a strong motivation for many people.

Tags: Diets and Weight Loss

About the Author

www.fda.gov
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.