Weight Loss Supplements: Pro vs. Con
The proponents and opponents of weight loss supplements both cite research to support their opinions. For the opponents, the claim is that there’s a lack of adequate research that supports the benefits of weight loss supplements, and the research that has been done is marginal. The proponents often overstate the benefits of studies that have been done on some weight loss supplements. What gives?
In my opinion, there are several problems. The first problem is attempting to apply the randomized, placebo-controlled trial used in pharmaceutical studies. Trials haven’t included enough subject groups or anywhere near enough subjects per group. The obvious answer is to use people who want to lose weight as subjects: put them on a diet and exercise program while you give half the supplement and the other half the placebo. Reasonable but not good enough. There should be at least four more control groups: normal-weight people with the supplement or placebo, and overweight people who take the supplement or the placebo without a diet and exercise program. Without doing that, no one really knows how much the supplement helps.
The second is not including enough variables. Weight loss and fat loss are obvious and are always included. Some include blood indicators: hormones such as ghrelin, leptin, and cortisol. Too often they don’t do measures of hunger and satiety with simple 0-10 scales. For the guy who criticizes the Food Frequency Questionnaire as much as I do, do I really think a simple hunger scale could be important? I do. For one thing, I think it would be a good predictor of whether people will stick with the study, and by extension, with the program in real life.
The final problem is the expectation of the researchers. I believe that researchers on both sides go in with an expectation of success or failure. They’re supposed to begin a study anticipating both outcomes equally, but I think there’s an inherent investigator bias; they’re just people, after all.
Given the problems, and believe me, this list could include at least a dozen more problems, are all weight loss supplements suspect? No, and I’ll give you my list of real contenders on Saturday.
What are you prepared to do today?
Dr. Chet
