Temporarily entering the world of insomniacs one night, I picked up the TV remote to see what those restless souls watched while most of us are off in dreamland. Between reruns of comedies on Nick at Nite and endless forecasts on the Weather Channel, I was captivated by a commercial hawking supplements to "boost your metabolism and burn away the fat." Astonished by the claims, I logged on to the Internet and began investigating.
It turns out such supplements are as prolific as an insomniac's sheep, with names like Liquid Clenbutrx, MD6, Metabolic Complete, Hydroxycut, Xenadrine RFA-1 and Stacker 3, to mention just a few. Some are available as liquids; others come in large, multicolored pills. But generally they promise the same thing: by speeding up your metabolism, they can reduce your fat, a claim I could not substantiate even after hours online and calls to several manufacturers.
These supplements are supposed to work by increasing thermogenesis--that is, by converting more of the food you eat into heat before it can be stored as fat. Being able to do this safely would, of course, be a welcome way to avoid the buildup of fat and keep off extra pounds. But there are few if any studies in the scientific literature showing that these products can do this effectively or safely. Even so, thanks to a marketing blitz, the supplements have become a multibillion-dollar industry.
What's distressing is that although they don't work, they are not risk free. Most contain the controversial ingredient ephedra (a Chinese herb also known as mahuang) or ephedrine. The U.S. Food and Drug Administration has received reports of 80 deaths and about 1,400 instances of adverse effects that may be associated with the use of the herb, and has issued strong warnings about the use of ephedrine-containing products. Their potential side effects include heart attack, stroke, seizures, psychosis and death. The products are even packaged with a long list of user warnings.
More dangerous still are variants containing combos of ephedrine, caffeine, pseudoephedrine and the more potent norephedrine. While the last two ingredients are used in common over-the-counter cold remedies, they can produce dangerous side effects similar to those of the banned drug methamphetamine.
If you want to increase your metabolism, there is really only one safe and reliable way to do it. Increase your physical activity--whether it's walking briskly, lifting weights or playing a vigorous game of tennis. Not only will the exertion help you shed some pounds, but it's also more beneficial to the heart and skeletal muscles. Keep your money in your pocket. There are no shortcut pills to a leaner body.
Dr. Ian appears on NBC's Today firstname.lastname@example.org