Why Are Cannabis Users Often Lean Despite The Munchies? Science May Have The Answer

Researchers in California have come up with a scientific explanation as to why cannabis users tend to be thinner and less diabetes-prone despite the munchies. The new facts should be a cautionary tale for teenagers to hold off before lighting up. 

According to a new study undertaken at the University of California Irvine and published in Science Direct, marijuana use during adolescence alters adult energy metabolism, and not in a good way. It is important to note that the research was done on mice, but as the authors noted the endocannabinoid system is found in most (if not all) mammalian organs and is involved in various physiological processes.

The study, in which adolescent mice were given low doses of THC, discovered that the effect goes into adulthood, disrupting energy balance and adipose organ (fat storage) homeostasis. These changes can affect both physical activity and mental processes like attention, which need a stable supply of brain fuel.

Mice that were given THC as adolescents but not as adults had reduced fat mass and increased lean mass. They were partially resistant to obesity and hyperglycemia, had higher-than-normal body temperatures and were unable to mobilize fuel from fat stores. Several of these features are also seen in people who frequently use cannabis.

Key Takeaways

• Regular marijuana use causes changes in fat cells making them produce proteins that are usually found only in muscle and the heart, impacting their ability to store and release nutrients.
• These changes could impact physical and mental processes that require a stable supply of nutrients to the brain.
• Molecular and functional adipose abnormalities identify this state as pseudo-lean.
• “Adolescent exposure to THC may promote an enduring “pseudo-lean” state that superficially resembles healthy leanness but might in fact be rooted in adipose organ dysfunction.”

“All too often we think of cannabis only as a psychoactive drug,” stated Daniele Piomelli, Ph.D., director of UC Irvine's Center for the Study of Cannabis, Louise Turner Arnold Chair in the Neurosciences and professor in the UCI's Department of Anatomy & Neurobiology.

“But, its effects extend well beyond the brain. Its main constituent, THC, mimics a group of chemical messengers called endocannabinoids, which regulate important functions throughout the body,” Piomelli added. “Our results show that interfering with endocannabinoid signaling during adolescence disrupts adipose organ function in a permanent way, with potentially far-reaching consequences on physical and mental health.”

The study was primarily funded by the National Institute on Drug Abuse.