Under the Radar: Is it the Weed or the Nicotine that’s Helping You Lose Weight?

It’s a touchy subject in most of the Western world – should marijuana be legal? Both sides marshal various arguments for and against legalisation.

One of the less advertised arguments for marijuana is its potential for weight loss. Jezebel’s article, “Smoke Weed and Be Skinny” (commenting on a study from 2013) jocularly advocates the “Stoner’s Diet” to help lose weight. Indeed, there seems to be a body of evidence (both anecdotal and peer-reviewed studies) that suggests marijuana users are typically less obese than their pot-free counterparts, seemingly in spite of cannabis’ appetite stimulation, which results in cannabis users eating more calories on average.

A new study, which has yet to generate much chatter, looks at whether the method of use plays a role. In particular, is the fact that cannabis is commonly smoked, mixed with tobacco, confusing our results? Nicotine is well-established as a means of weight control. So what helps you lose weight – marijuana, nicotine, or both?

This new work looked at Canadian teenagers, who were 12-13 years old when they entered the study, and had their body mass index (BMI) and waist circumference (WC) measured from 17 years of age until their early twenties. The participants’ tobacco and marijuana smoking habits were recorded (number of tobacco cigarettes per week, marijuana uses per week).

The data was then split according to tobacco use, and the change in BMI versus marijuana use for non-smokers (max 0.5 cigarettes per day) and frequent tobacco smokers (15 per day).

So How Does Nicotine Affect Marijuana Users’ Weight?

The answer is complicated. What’s more, it seems to be different for men and women. For men who smoked infrequently, the relationship is “U-shaped”. Low cannabis use was associated with higher BMI change (about 2 points over the approximately 5 year period), but in those using cannabis at moderate levels, this association disappeared (little to no BMI change). In those with higher cannabis use, the association reappeared! For men who smoked frequently, the relationship was “inverted-U shaped” – moderate cannabis users experienced the greatest BMI change. Women, regardless of their cigarette smoking habits, showed the U-shaped relationship.

The Bottom Line?

It’s still not clear that smoking cannabis helps you lose weight. The authors themselves note that there may be hidden variables in the data – the individuals in the study may not have reported their cannabis use accurately, and precisely how cannabis was ingested was not recorded in the data, nor was the use of other illicit substances.

In short – we’re far from declaring marijuana a weight loss supplement, no matter what some websites might indicate.

Dubé, E. et al. (2015). Cigarette smoking may modify the association between cannabis use and adiposity in males. Pharmacology Biochemistry and Behavior. DOI:10.1016/j.pbb.2015.04.018

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

Penner E. A. et al. (2013). The Impact of Marijuana Use on Glucose, Insulin, and Insulin Resistance among US Adults. The American Journal of Medicine. DOI:10.1016/j.amjmed.2013.03.002

Rodondi, N. et al. (2006). Marijuana Use, Diet, Body Mass Index, and Cardiovascular Risk Factors (from the CARDIA Study). American Journal of Cardiology. DOI:10.1016/j.amjcard.2006.03.024