Preclinical studies indicate increased food intake and weight gain as effects of cannabinoids. However, cross-sectional epidemiological studies indicate a lower prevalence of obesity among cannabis users. Marijuana use has long been associated with the incessant consumption of snacks. Smoking marijuana is known to increase appetite, a sensation known colloquially as “cravings”.
Because of this common side effect, people often assume that chronic marijuana use causes weight gain. Current evidence suggests that regular cannabis use promotes weight gain. Like previous researchers, they found a lower prevalence of overweight and obesity among the cohort that used marijuana. Another study revealed that THCV's weight-loss powers stem in part from its ability to calm the brain's default mode network (DMN).
Marijuana can cause weight gain due in part to the ability of THC to increase the hormone ghrelin, which stimulates appetite. Drugs that block CB1, such as rimonabant, cause significant weight loss, but the side effects are serious. Cannabis was associated with little or no weight gain in observational studies, but with weight gain in some higher-quality studies (clinical trials). By activating CB1, a receptor present in various tissues in the body, the THC cannabinoid in cannabis can increase appetite.
In addition, in a study of patients with cancer in which weight gain did occur, this was lower than the comparison drug (megestrol).
Tetrahydrocannabinol(THC), a cannabinoid in cannabis, can bind to the type 1 cannabinoid receptor (CB) and thus promote overfeeding and weight gain. But beyond these acute effects on appetite, are there more sustained relationships between marijuana use and body weight? In this edition of The Interface, we examine these possible relationships through a literature review. This mechanism provides strains (cultivars) high in THC with their characteristic hunger effects, known as cravings.
However, in the case of these medical conditions, while appetite may be stimulated, some studies indicate that weight gain is not always clinically significant. In empirical support of this conclusion, Vemuri et al1 state that endocannabinoids are important biomedical and metabolic regulators in mammalian physiology, with diverse and ubiquitous modulatory actions, including the regulation of body weight. For example, in a six-week study with 243 Swiss patients with cancer-related cachexia, researchers compared the weight-inducing effects of cannabis extract with those of placebo. The antagonism of this cannabinoid receptor site should lead to a reduction in caloric intake and subsequent weight loss.
Theoretically, a THC-induced growling stomach and heightened senses create the perfect storm for overeating and weight gain.