Why Diet Drugs Can Be Diet Dangers

Diet pills and supplements can promote weight loss, but they also can carry big health risks. Don’t be dazzled by ads promising miracles.

If you’ve ever wished you could lose a few–or many–pounds in a fast and easy way, chances are you’ve paid attention to headlines like these in advertisements seen everywhere these days. Even some serious publications run full-page ads that promise, with lots of exclamation marks, that a company’s pills, drinks, or supplements will make your extra pounds miraculously melt away.


Teens seem particularly vulnerable to such ads. They can be influenced by their own self-image–and sometimes subtly by peers, parents, and coaches–to lose weight in order to look good, perform better, or be more popular.

The Centers for Disease Control and Prevention conducted a study of 11,631 high school students and found that more than 43 percent of the girls surveyed said they were “on a diet.” The most common dieting methods used were skipping meals, induced vomiting after eating, and taking diet pills. Diet pills can be effective in helping some people lose weight, but are they right for you?

Straight from the Supermarket

Over-the-counter weight-loss drugs such as Acutrim and Dexatrim contain phenyl-propanolamine (PPA), an appetite suppressant that affects the central nervous system. When combined with changes in eating habits and exercise, PPA can help people lose weight. However, the results are temporary and should only be used for the short term (not more than three weeks) until new eating habits are established.

Experts warn that appetite suppressants are most effective in people who are obese, meaning their weight is at least 20 percent over their ideal body weight, as indicated on the body mass index (BMI) chart on page 11. Anyone who is only slightly overweight or simply wants to improve his or her appearance should not use these drugs.

In fact, medical experts warn that teens should not take medication containing PPA unless it is ordered and supervised by a doctor. This is the opinion of Michael Weintraub, M.D., who recently served as a director of drug evaluation at the U.S. Food and Drug Administration (FDA). “PPA is not recommended for teens,” says Dr. Weintraub, “because they are still growing, and if they suppress their appetites, they may not get proper nutrition.” If your doctor does recommend an over-the-counter diet pill, follow his or her dose instructions precisely. PPA can cause severe high blood pressure and an irregular heart rhythm when taken in high doses.

Are Prescriptions Better?

Even diet pills that are prescribed by a doctor may not be completely safe, either. In 1997, the drugs fenfluramine and dexfenfluramine (the “fen” part of the fen-phen combination often prescribed) were taken off the market. Although these drugs were effective in curbing the appetite, they were linked to heart valve disease as well as a condition called primary pulmonary hypertension. With this condition, there is an increased resistance to blood flow through the lungs. That puts strain on the heart and can lead to heart failure. In October 1999, the company that made Pondimin and Redux (the trade names for the withdrawn drugs) agreed to pay about $4 billion to thousands of people who had evidence that their health was harmed by the drugs.

But new pills have taken their place. Meridia is one such prescription drug that is designed to increase metabolism, cause a feeling of fullness, and increase a person’s energy level. Studies show that people who took Meridia had a significant loss of weight, BMI, and waist circumference when they used it along with a low-calorie diet, exercise, and behavior modification. This drug is recommended only for people with a BMI of over 30.


Mike Myers, M.D., a physician in Los Alamitos, California, says that Meridia has its place and can assist with weight loss, but it is not a wonder drug. Meridia’s side effects include dry mouth, insomnia, constipation, increase in blood pressure, and a rapid pulse.

What About Herbals?

The latest craze in weight-loss drugs are herbal products that also can carry a risk. Metabolife, Herbal Phen-Fen, and other similar “natural herbals” contain the herbal supplement ephedra, also known as ma huang. Ephedra, chemically related to amphetamine, can have potent side effects. In one case, a 20-year-old Marine became psychotic (afflicted with a serious mental disorder in which one loses contact with reality) while using a supplement containing ephedra. Once he stopped using it, he returned to normal. Other possible side effects include sleeplessness, restlessness, irritability, headache, nausea, vomiting, urinary disorders, and rapid heartbeat. Also, these products can be very dangerous to people with existing health conditions such as high blood pressure.

Overdosing on ephedra can cause a rise in blood pressure, changes in heart rhythm, severe sweating, enlarged pupils, seizures, and fever. Between 1993 and 1997, 34 deaths and 800 medical and psychiatric complications were reported in people using ephedra. Neal Benowitz, M.D., a toxicologist and professor at the University of California at San Francisco, says, “I would prefer to see ephedra pulled off the market until adequate warnings can be developed.”

Unlike prescription drugs, herbals are considered dietary supplements, not drugs, and do not go through the FDA approval process for safety and effectiveness. At times, the herbal product doesn’t even contain the stated amounts of ingredients on the label. And the manufacturer’s claims are usually not confirmed by medical research. “People assume that if it’s natural it must be safe,” says Gail Mahady, an expert on medicinal plants at the College of Pharmacy at the University of Illinois at Chicago. “But ephedra is a drug.”

Herbals and prescription diet pills are designed to be used for the short term to help with lifestyle changes. Drugs alone offer only temporary solutions and, in some cases, may jeopardize your health.

Diet Claims: Fact of Fiction?

When you turn on the television, open the newspaper, or read a magazine, you most likely will find someone promoting a “miracle weight-loss product.” These ads claim that the products will help you lose all the weight you want with the least amount of effort. But do they really work, or are these products just full of hot air? Let’s look at some manufacturing claims and the truths behind them.

Claim: Lose weight while you sleep.

Fact: Losing weight requires significant changes in the type and amount of food you eat and the burning of calories through increased physical exertion such as exercise. A product that claims weight loss without any kind of sacrifice or effort is bogus.

Claim: Lose weight and keep it off for good.

Fact: Maintaining long-term weight loss requires permanent changes in diet and exercise. Be skeptical about any claim that a product will enable you to keep any weight off permanently.

Claim: John Doe lost 84 pounds in six weeks.

Fact: Just because someone pictured in an ad lost a lot of weight doesn’t mean you will, too. Don’t be misled.

Claim: Lose all the weight you want for just $99.

Fact: You may pay $99 up front, but there are usually hidden costs in the program. For example, some programs don’t publicize the fact that you also have to buy prepackaged meals at costs greater than program fees. Before you sign up for any weight-loss program, ask for all the costs in writing.

Claim: Lose 20 pounds in just three weeks.

Fact: As a rule, the faster you lose weight, the faster you gain it back. Plus, fast weight loss can harm your health. Unless you have a medical reason, don’t look for programs that promise quick weight loss.

Claim: Scientific breakthrough! Medical miracle!

Fact: Unless the miracle involves reducing your caloric intake and increasing your physical activity, ignore it. The most effective weight-loss programs encourage a modest reduction of food intake of 500 calories per day. At this rate, you will cut 3,500 calories per week, which is equal to one pound of fat. That’s a loss that you can live with long-term.