This week we’re busting another weight-loss supplement scam. There were many to choose from and I settled on green coffee beans. The theory is that caffeine decreases fat absorption and something called chlorogenic acid influences the metabolism of sugar and fat. Dr. Oz championed green coffee beans on his TV show and website. He even went so far as to sponsor a study! Some of his fans agreed to take a green coffee bean supplement for two weeks and they lost two pounds each. Volunteers not taking green coffee bean extract lost one pound in two weeks.

But we can’t just let Dr. Oz get off that easy! Let’s dive into the real research.

A study conducted in the lab found that extract of green coffee beans could cause fat cells to release their fat. Not very applicable to people.

Three studies in obese mice have shown mixed results.

The crux of the evidence for green coffee beans comes down to one randomized, controlled trial involving 16 overweight adults. Each participant took a high dose of green coffee bean extract, a low dose of coffee extract, or placebo for six weeks each, in different orders. For example, Person A took 1,050 mg green coffee extract for six weeks, then waited for a two-week “washout” period, then took the placebo pill for six weeks, then waited for a two-week “washout” period, then took 700 mg per day for six weeks.

All of the participants lost weight over the 22 weeks of the study.

But here’s the kicker: all the subjects lost weight over the course of the study and all the subjects received diet counselling on a weekly basis. If anything, I would say this study shows that receiving weekly counselling about weight loss can help people lose weight.

When it comes to green coffee beans, there just is not a body of evidence showing it will help you lose weight.

Many weight-loss supplements contain caffeine. My personal theory is that caffeine is helpful insofar as it affects willpower. If your energy is low, you are more likely to give in to a craving for junk food. You are more likely to engage in a sedentary activity than an active activity. Caffeine provides an energy boost that helps you stick to positive resolutions.

Caffeine use can backfire if it interferes with your sleep or causes anxiety, both of which will tire you out. That’s just my theory.

In the next Nature’s Way column we’re going to cover the first of two supplements that may actually be useful to take while losing weight. There are no supplements that will take the place of changing your diet, but these supplements have a legitimate role for people who are in the process of losing weight. Stay tuned!