There Are No Magic Pills

When I heard that the FDA had approved a new diet pill, I was intrigued. Despite the many weight-loss products available at drugstores and over the internet, there are very few drugs that the FDA has approved for weight loss, and some drugs that were approved have been taken off the market because of safety concerns.

Having been through my own process of losing weight and learning how to stay healthy, I know that there is no easy fix. Having friends who have struggled with their weight, I know that there is no one-size-fits-all solution. So, I was interested to see how Belviq works.

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According to the prescribing information, Belviq is a serotonin 2C receptor agonist that controls appetite by binding to serotonin receptors in the brain. That could be effective if the reason that you are overweight is because you have too much of an appetite, but my own food issues stem from eating when I am tired, stressed or bored–not from excess hunger.

The prescribing information summarizes the results of three randomized, double-blind, placebo-controlled trials conducted over 1 or 2 years. In the studies, Belviq was taken twice a day in conjunction with counseling on “reduced caloric intake” and “increased physical activity” that continued every four weeks throughout the trial.

It is striking that a large number of subjects (36-50%) withdrew from each study before the first year was completed. We all know how quickly New Year’s resolutions fall to the wayside, but you would think that the extra structure of a clinical trial would keep people motivated–maybe they got tired of the study requirements.

The clinical trial data show that statistically significantly greater weight loss was achieved with Belviq, but the numbers make me wonder whether it is worth the costs and risks. The year 1 placebo-adjusted weight loss achieved in patients treated with Belvig was 3.3 kg (7.25 lbs) in a patient population with an average starting weight of about 100 kg (220 lbs). (That’s about one “week” of weight loss on The Biggest Loser!) The raw numbers showed an average weight loss of 7.9 kg (17 lbs) for the Belviq group and 3.7 kg (8 lbs) for the placebo group.  That is a big difference, but considering the starting weight of the patients and the duration of the study, I’m not sure if it’s worth it.

I have even more questions looking at the Year 2 study data.

Patients in all three Year 2 patient groups (BELVIQ Year 1/ BELVIQ Year 2, BELVIQ Year 1/placebo Year 2, and placebo Year 1/placebo Year 2) regained weight in Year 2 but remained below their Year 1 mean baseline.

Been there, done that!

The raw numbers from the Year 2 study showed an average weight loss of 6.0 kg (13 lbs) from starting weight for the 2-year Belviq group and 2.6 kg (5.7 lbs) for the 2-year placebo group.  If I were starting at 220 lbs, I’d rather end up 13 lbs lighter than 6 lbs lighter, but I don’t know if losing those extra 7 pounds is worth the costs and risks of taking a prescription weight-loss drug twice a day for two years.

The report doesn’t examine the reasons behind the weight gain in year 2. Was the drug less effective at controlling appetite? Did the patients disregard the diet and exercise counseling? If patients continued for a third year, would the weight gain continue? level off? decline again?

Belviq may offer hope to those who have given up on getting to a healthy weight. It may help people get started on a diet and exercise plan, and encourage them with weight loss results. But what the clinical trial data mean to me is that there is no magic pill. You can do almost as well with diet and exercise and you can do better if you learn to make permanent lifestyle changes that support healthy choices. But that’s just my very humble, non-expert opinion.