“Although marijuana use is commonly associated with increased appetite and the likelihood of weight gain, research findings in this area are mixed.

Most studies, however, report cross-sectional associations and rarely control for such important predictors as physical activity, socioeconomic status, and alcohol and other drug use.

Results show that daily female marijuana users have a BMI that is approximately 3.1% (p<0.01) lower than that of non-users, whereas daily male users have a BMI that is approximately 2.7% (p<0.01) lower than that of non-users.

The present study indicates a negative association between marijuana use and BMI.

Uncovering a negative association between marijuana use and weight status is a valuable contribution to the literature, as this result contradicts those from some previous studies, which were unable to address time-invariant unobserved heterogeneity.”

http://www.ncbi.nlm.nih.gov/pubmed/27572145

“Daily Marijuana Use Linked to Lower BMI”           http://www.livescience.com/56068-daily-marijuana-use-linked-to-lower-bmi.html

“Marijuana Makes You Skinny? New Study Says Pot May Lead To Lower Body Mass Index” http://www.ibtimes.com/marijuana-makes-you-skinny-new-study-says-pot-may-lead-lower-body-mass-index-2414737

“Smoking marijuana can lower your BMI, study finds”  https://www.rawstory.com/2016/09/smoking-marijuana-can-lower-your-bmi-study-finds/