Why Supplements Don't Work for Weight Loss

Published: November 11th, 2013   |   Author: Jessica Levine

Know the risks of diet pills so you won’t be tempted to try one.


You see the ad with impressive before and after photos, you hear about a friend of a friend who lost 20 pounds practically overnight, you’re drawn to a flashy display in the drugstore and think, "Why not?". There are many ways you might be persuaded to try a weight loss supplement. “Pills are attractive to people who like quick fixes,” says Jamie Kane, MD, a weight loss specialist in New York. “Unfortunately, there are no quick fixes when it comes to weight loss.”

The Risks
While some of these pills may work to increase your metabolism and help you lose weight, you have to ask yourself what the real cost may be. “While people may believe in (and see) the desired results, these pills may interfere with overall health,” says Lauren O’Connor, MS, RD, a Los Angeles–based dietitian. “None of these diet pills are without consequence.” Ephedra, for example, did help people drop pounds—but some of them also dropped dead. That’s why in 2004 the FDA banned supplements containing it after finding they put users at risk for heart complications and death. According to the National Institutes of Health, using ephedra could worsen health conditions like heart disease, kidney disease, and diabetes—not to mention anxiety, high blood pressure, insomnia, and a number of other problems.

“Supplements are unregulated and thus anyone can say anything about a weight loss supplement without having the requirement of FDA approval,” says Darwin Deen, MD, a medical professor at City College of New York. Since supplements are not subject to the same safety standards and testing as prescription drugs, it’s a buyer-beware situation. Some of them can be dangerous, but only once they’ve been on the market long enough to prove themselves does the FDA step in. “The worst-case scenario is major illness or death,” Dr. Kane says. “Liver toxicity is a concern as well.”

In fact, recently a case was reported at a meeting of the American College of Gastroenterology in which a 52-year-old woman who took the diet pill SlimQuick, which contains green tea extract, for only 2 days ended up with liver failure, needing a transplant.

“I had a patient who had weighed 350 pounds, took a supplement for a few weeks, went into immediate heart failure, gained almost 100 pounds of water weight during that time and was on death’s door,” Dr. Kane says. “The unsupervised use of an unregulated medication (even if it is herbal) [can be very dangerous].”

“But What About________?”
Maybe you heard raspberry ketones, for example, really work. Here’s what the experts said about 10 weight-loss supplements you may have heard of.

  1. Bitter orange: “It contains the chemical Synephrine, which is similar to the main ingredient in ephedra,” O’Connor says. “Taken alone or with caffeine, bitter orange has been noted for raising heart rate and blood pressure—cautionary risk factors for heart disease. Why put your heart at risk?”
  2. Chitosan: “It has not been shown to be effective,” Dr. Kane says. And side effects like upset stomach, nausea, gas, increased stool bulk, and constipation have been noted.
  3. Chromium: “You might have marginal improvement in blood sugars, probably not on weight,” Dr. Kane says. Some health concerns like headache, insomnia, irritability, mood changes, and cognitive dysfunction have been noted.
  4. CLA: “Some studies have shown modest improvements in body composition, but there are concerns about increasing insulin resistance which would defeat the purpose,” Dr. Kane says. Side effects could include upset stomach, nausea, and loose stools.
  5. Green coffee extract: “Caffeine can have notable side effects including jitteriness, rise in blood pressure, and even heart palpitations,” O’Connor says. “If this particular concentration has no potential for such effects, that would be surprising to me, regardless of the claims.”
  6. Green tea extract: “There are some studies, but you don’t know exactly what you are buying,” Dr. Kane says. And there’s the caffeine again. Sure green tea’s EGCG has been shown to be effective in studies, but after the SlimQuick incident described above, we’d suggest sticking simply to a cup of tea brewed from a bag.
  7. HCG: “Another scam,” Dr. Kane says. “It has not been shown to be effective in any serious study. If a doctor is offering HCG for weight loss, beware.” He says the diet often involved very low calories—around 600—and other weight loss supplements.
  8. Hoodia: “It’s purported to have appetite suppressive effects,” Dr. Kane says. “But there’s no significant data to back up the claim.” There’s also no evidence that it doesn’t have side effects or safety concerns.
  9. Orlistat: “Orlistat, because it was first considered a drug, has the most data and it is effective,” Dr. Deen says. “But how long people should take it is the problem—it can reduce the absorption of fat-soluble vitamins, so should not be taken for more than a few months. And then what do you do? Regain the weight.” The infamous side effects including gas, loose stools, and “anal leakage,” should be enough to make you think twice.
  10. Raspberry ketones: “I've seen a lot of testimonials and a lot of marketing claims but have found very little reputable research to back the health claims,” O’Connor says. And she says the actual raspberry extract is likely replaced with a synthetic substance in these products to bring cost down.

Why Most Don’t Work
“I have many patients who have tried combinations of these products, but have yet to see anyone lose a significant amount of weight without making real changes to their diet,” Dr. Deen says. “Most people don’t recognize that medications for chronic diseases don’t work like the drugs for infections: Chronic diseases like diabetes, high blood pressure, cardiovascular disease, and obesity are not treated and resolved with medication. Because these diseases stem from lifestyle problems, the solutions must include lifestyle changes.”

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