Get stoned, drop pounds. Right?

In trolling the headlines for a writing topic, I ran into this irresistible headline: Does pot prevent obesity? What new marijuana study says.   

The headline is reasonably noncommittal, but that ends quickly:

Move over, fad diets. Scientists have identified something else that might keep off excess weight.

Smoking pot.

That’s right, marijuana users are less likely to be obese than their non-toking counterparts, according to a new study.

Buried much deeper in the piece is the cautionary, “The study didn’t actually prove smoking pot causes weight-loss.”

The reporting is typically sensationalist and deceptive, but the study itself was linked in the article, which is worth a bunch of Schwitzer points in my book.  Let’s take a look.

The authors give us a good justification for looking into Obesity and Cannabis Use.  As they say, cannabis and endocannabinoids have long been suspected of having significant effects on appetite and weight, so they took the easiest route to looking for an association: mining previously-done surveys for data.  The two surveys provided self-reported data on cannabis use and on height and weight.

After crunching the data, the authors found that cannabis users were significantly less likely to be obese than non-users, but they quite explicitly acknowledged possible biases (emphasis mine):

Our results should be interpreted in the context of several limitations. Firstly, information on cannabis use, height, and weight was based on self-reports and was not confirmed by direct measurement. Self-reports tend to underestimate BMI but are unlikely to influence conclusions about associations, since they are unlikely to be related to cannabis use (WTF. –ed.)…Secondly, physical activity and diet are 2 major risk factors for obesity but were not taken into account in this study. Despite these limitations, this analysis showed that even if cannabis consumption increases appetite, people using cannabis are less likely to be obese than people who do not use cannabis.

Given their admission of the obvious problems with this study, it’s curious that they should conclude that ” people using cannabis are less likely to be obese than people who do not use cannabis.”  This seems, from the data they’ve given us, a bit of a stretch given the limitations of the study.

This doesn’t make for sexy headlines, but it’s a lot closer to the truth: a single epidemiologic study has found some evidence that reported cannabis users have a lower reported obesity rate than reported non-users.  There is no evidence of causality.  At most, this could lead to a study better designed to answer the question.  At most.


Le Strat, Y., & Le Foll, B. (2011). Obesity and Cannabis Use: Results From 2 Representative National Surveys American Journal of Epidemiology DOI: 10.1093/aje/kwr200


  1. Anonymouse

     /  September 7, 2011

    Watch “The Union: The Business behind Getting High”. It is a big eye-opener. Joe Rogan has some great commentary as well in the doc. Cannabis can be indica, sativa, or hybrid of the two. Each strain effects ea h person differently, but with some common shared affects. How it affects the user depends solely on that user. Cannabis for cancer patients help them eat because they want to eat but can’t from the uncomfortableness of chemotherapy. A nice indica like grand daddy purple will help them out.

    • saffronrose

       /  September 7, 2011

      A few years ago, my pdoc said there was a weight-loss drug coming down the pike which used either cannabinoids OR worked on the same part of the brain they do. Allegedly it had none of the disturbing side effects of most of the weight loss drug, nor any of cannabis.

      I’m waiting for that, and for the cough syrup derived from theobromine. I can’t handle codeine/vicodin, you see, and therefore no heavy-duty cough syrup is available to me.

      • IIRC, the cannabanoid antagonist crapped out because of significant side effects including severe depression. Sorry….

        • saffronrose

           /  September 7, 2011

          Drat. Just what an overweight bipolar needs to hear. Thanks for the update–I had been wondering what happened to it.

  2. Duen De

     /  September 8, 2011

    ” Between 0.7 and 1.8 percent of the sample smoked marijuana three times a week or more.”
    I think a lot of people aren’t telling the truth. Where I live (British Columbia, Canada) half of the males under 60 that I know smoke 3 times a day! And they are skinny because they would rather spend their last $50 on weed than Mcdonalds.

  3. Alright. I’ll participate in the follow up study. It’s just something I feel morally obliged to do. Though I have a feeling that the results will largely depend on whether or not the study is carried out near a Del Taco.


  4. Well, Lil Wayne is actually little, and he self-reports copious consumption. It’s also likely that he consumes copious amounts of what-have-you else in addition to cannabis, so maybe there are other contributing factors.

    I do have a correlation: According to my two minutes of intensive Googling, Denver has approximately one fucktillion medical marijuana dispensaries. I think they actually outnumber Starbucks stores. And…. Colorado is the only state with an obesity rate under 20%.

  5. DLC

     /  September 12, 2011

    Too often I hear marijuana legalization advocates making all kinds of claims for medical use. They list a whole boatload of conditions which using is supposed to treat or cure, when in reality all most of them are doing is winking broadly and suggesting they be left to their devices. Personally, I don’t care if you want to inebriate yourself, so long as you do so safely. What does bother me is people trying to backdoor legality by making all sorts of medical claims, most of which are either unprovable, dubious or already disproved.

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