The Skinny on Diet Pills
Heather Bauer, R.D., nu-train
With the release of Alli this past June, diet pills are once again in the spotlight. The claims are appealing: "Lose 30 lbs in 30 days" or "Melt your fat away". But, do these pills really work? And more importantly, are they even safe? We've broken down for you some of the more popular over the counter and prescription diet pills on the market to let you decide for yourself. As a disclaimer, we believe that there are no magic pills to get you to your goal - changing your lifestyle is the only truly tested and effective method.
Research regarding prescription drugs is more thorough and credible since they have to be approved by the Food and Drug Administration. Prescription weight loss drugs are intended for individuals with medically significant weight problems, and are intended to be used in conjunction with dietary, behavioral, and exercise programs. If used correctly by the intended group of users, oftentimes they can be a lifesaver. For those who do not fit the description of the intended user, or for those who simply take the pills without changing their lifestyle, expect disappointment.
Orlistat (Brand name prescription drug: Xenical; OTC drug: Alli)
How it Works: Orlistat blocks the absorption of fat by working on the digestive system. It is claimed to inhibit the action of an enzyme called lipase, which breaks down dietary fat so the body can absorb it. Orlistat blocks the absorption of up to 30% of dietary fat, and the unabsorbed fat is eliminated through the stool.
Research: According to the FDA, before orlistat was approved in 1999, it was tested in seven clinical trials, in which more than 4,000 obese individuals participated. Each of these trials used orlistat in conjunction with a low-calorie, low-fat diet, and an exercise routine. Overall, 57% of people taking orlistat lost at least 5% of their body weight as compared to 31% who took a placebo.
Side Effects: Due to the fact that unabsorbed fat will exit through the stools, many gastrointestinal side effects may exist. Perhaps most embarrassing is that users may experience oily rectal seepage and in extreme cases, may need adult diapers. Fecal urgency, gas with discharge, and frequent, oily bowel movements are also possible. In addition, orlistat interferes with the absorption of fat-soluble vitamins (A,D,E, and K) and may also limit the absorption of healthy fats like fish oil or flaxseed oil. As a result, nutritional deficiencies may occur.
Sibutramine (brand name: Meridia)
How it Works: Sibutramine is a monoamine reuptake inhibitor, which means that is blocks the reabsorption of certain neurotransmitters, or messengers to the brain. This allows the levels of these neurotransmitters to increase, which then helps to control appetite. Thus, sibutramine is mostly an appetite suppressant.
Research: Manufacturers report several double-blind, placebo controlled trials. There was evidence that various levels of sibutramine led to significantly more weight loss in obese individuals, than for those who used the placebo. As with orlistat, these studies were done in conjunction with a healthy eating and exercise plan.
Side Effects: The most common side effects are dry mouth, anorexia, headache, insomnia, and constipation. Some users also experience an increase in blood pressure and heart rate.
Over the counter weight loss drugs are not subject to approval or regulation by the FDA. As a result, we have limited research on the hundreds of OTC diet pills out there, and almost no long-term research. In addition, because these pills aren't regulated, they may not even have the amount of an effective ingredient that is stated on the bottle. There are hundreds of diet pills out there. This is only a small sample.
The only FDA approved OTC drug. See orlistat (above).
How it Works: Trimspa, endorsed by the late Anna Nicole Smith, has many different ingredients in it. Unfortunately, TrimSpa no longer lists each of the ingredients separately, but rather states that it has a "x32 proprietary blend". We were able to uncover some of the ingredients. Ingredients like caffeine, bitter orange, and green tea extract are thought to work as stimulants. Hoodia, chromium, and glucomannan (fiber) are proposed to work as appetite suppressants.
Research: Clinical trials have not shown that the ingredients in TrimSpa can reduce body fat. There is some evidence that green tea extract may aid in weight loss, and there is clear evidence that fiber (i.e. glucomannan) will lead to satiety, thus decreasing one's appetite. However, none of the ingredients have been significantly proven to lead to weight loss.
Side Effects: Due to the fact that many of the ingredients have been insufficiently tested, there is concern that in large doses, some of these ingredients may be harmful. Bitter orange (naringin) may interfere with many common prescription drugs such as antiarrhythmics, anticoagulants, statins, immunosuppressants, calcium channel blockers, and protease inhibitors. Ingredients in TrimSpa may lead to insomnia, anxiety, palpitations, and restlessness. TrimSpa may also cause migraines in susceptible people since it contains cocoa extract which contains tyramine. Hoodia, a popular ingredient on its own, and thought to suppress appetite, is also still in the beginning research stages. There is a possibility that it can lead to liver toxicity. Moreover, Hoodia is a protected plant, and because OTC diet pills are not regulated, most of the pills don't have as much Hoodia as is stated on the packaging.
How it Works: As with the TrimSpa, Xenadrine has a long list of ingredients. These include green tea leaf extract, bitter orange, caffeine, cocoa extract, grapeseed extract, ginger root, and guarana. These ingredients are purported to speed up the metabolism.
Research: Though proponents of Xenadrine claim numerous clinical trials have been completed, it was hard for us to find any. The two we did find were extremely small studies of six and ten subjects. In addition, we found it dodgy that the Xenadrine website listed "returning shortly..." under the tab for clinical studies. When we called the company, they could not elaborate.
Side Effects: The same side effects noted for specific ingredients in TrimSpa are noted here. In addition, people taking Xenadrine have noticed nausea and upset stomachs, anxiety, shaking, cramps, increased heart rate, and increased sweating.
There are hundreds of other diet pills out on the market. Most of the OTC diet pills rely on the fine print that states it must be combined with a low-calorie diet and exercise. In reality, if you followed the healthy diet and exercise portion, you would lose weight. However, in certain cases, prescription drugs may be helpful and/or necessary, but that must be determined by your physician. With all diet pills remember - if it sounds too good to be true, chances are it is.