“Buyer beware” is the message consumers should remember when purchasing dietary supplements for weight loss, says Judith S. Stern, vice president of the American Obesity Association in Northwest.
“I am optimistic for development of new drugs for basic causes of obesity, but right now on the over-the-counter market… there are exaggerated claims,” she says. “They usually have testimonials that aren’t true.”
Diet products, either prescription or dietary supplements, always seem to be at the center of controversy. Doctors continue to debate whether the products are effective at achieving weight loss and how dangerous the side effects might be.
This month, the Cleveland Clinic Journal of Medicine published a study saying “evidence is weak that any of the commonly used alternative products is effective for reducing weight in moderately overweight individuals.”
Right now, the only prescription drugs approved by the Food and Drug Administration for the long-term treatment of obesity include sibutramine, also known as Meridia; and orlistat, also known as Xenical.
For short-term treatment of obesity lasting a few weeks, the government organization also approved Phentermine, also known as Adipex; and diethylpropion, also known as Tenuate.
Anyone trying to lose weight should be under the care of a physician, says Dr. Ramin Oskoui, clinical cardiologist at Washington Hospital Center. He says people should not take dietary supplements for weight loss without the advice of a doctor, especially because other medications could react poorly with the diet product.
In fact, Dr. Oskoui says gastric bypass surgery for weight problems has become far more safe and effective than taking diet products.
“Sustained weight loss is best achieved with a combination of diet and exercise,” he says. “When you weigh 350 pounds, and you should weigh 175 pounds, there is no pill that will get you there, but there are a number of pills that will get you in trouble. ... People have paid a price for trying to lose weight this way.”
In 1997, the FDA removed the prescription drugs fenfluramine and dexfenfluramine from the market. However, it did not withdraw Phentermine, the third-most commonly used obesity drug.
Of the patients evaluated for taking fenfluramine and dexfenfluramine, about 30 percent of them had abnormal echocardiograms. The organization stated that “these new findings suggest fenfluramine and dexfenfluramine are the likely cause of heart valve problems of the type that prompted FDA’s two earlier warnings concerning ‘fen-phen,’ a combination of fenfluramine and Phentermine.”
When fen-phen first came out, it looked like it was a good drug, but some people developed heart valve abnormalities, without presenting obvious symptoms, says Dr. Rick Morrissey, chief of cardiology at Georgetown University Hospital.
“If you took fen-phen, and you haven’t been evaluated, you should see your primary care doctor or cardiologist,” he says. “The FDA tries to do the best they can on medications, but we find out more about it once it’s released to the general population.”
Further, in April, the federal government banned dietary supplements containing ephedra. In June, a jury awarded $7.4 million to Rhea McAllister, who suffered a stroke after consuming the stimulant in a Metabolife supplement.
Margaret Peet, senior vice president of sales at GNC in Pittsburgh, says the company, which is the largest U.S. vitamin and dietary supplement chain, does not make claims about third-party products on their shelves. GNC has its own line of products, in which the company is completely confident.
“We have them available for consumers if they would like to buy them,” she says. “Choice is everything in the world, isn’t it?”
However, Ms. Peet says products developed by GNC have undergone clinical trials. One such product is Total Lean Control, which contains a combination of guarana seed extract, black tea, grape skin extract, ginger and other herbs.
“That’s been clinically proven to reduce calorie consumption of food intake,” she says. “Our products have undergone 150 quality checks before they arrive on the shelves. They are very safe.”
NSF International in Ann Arbor, Mich., evaluates the GNC products, Ms. Peet says. With the passage of the Dietary Supplement Health and Education Act of 1994, dietary supplement manufacturers are responsible for determining the safety of the products before they are sold.
The FDA is responsible for taking action against any unsafe dietary supplements after they reach the market. The organization works closely with the Federal Trade Commission to evaluate advertising and labeling.
Through the Freedom of Information Act, persons can request to find out what adverse events have happened in relation to dietary supplements. People can report complaints to their local FDA office, according to FDA officials.
It’s particularly disturbing that people with eating disorders, such as anorexia or bulimia, have such easy availability to diet products, says Dr. Graham Redgrave, an eating disorders attending physician at Johns Hopkins Medical Institutions in Baltimore.
“For these patients, becoming thin is part of an illness,” he says. “The pills are reinforcing the illness rather than helping them become more healthy.”
Further, Dr. Redgrave says he also worries about young people who are overweight who seek to change their bodies by means of the dietary supplements.
“They are really putting themselves at risk for developing problem eating behaviors, like binge eating or other full-blown eating disorders,” Dr. Redgrave says. “Young people who diet usually gain weight over time.
Rather than going on crash diets and using supplements to help, it’s much better to change one’s lifestyle and the way one eats and exercises.”
However, 64.5 percent of the population in the United States is overweight, according to the American Obesity Association.
Some of those people can’t lose the pounds through conservative means and prescription diets pills under the supervision of a doctor may be a good idea, says Dr. Arthur Frank, medical director of George Washington University Weight Management Program in Northwest.
“You can ‘out-eat’ anything I can give you, but [prescription pills] can be helpful if a person is struggling and needs a little bit of help,” Dr. Frank says. “There’s some risk involved in doing nothing. Then, it leaves your obesity in place.”
Revision date: June 21, 2011
Last revised: by Janet A. Staessen, MD, PhD