Thomas Clark, PhD, has always specialized in mosquitoes, but now he's being distracted by marijuana. Outside of his regular job as professor and chief of biological sciences at Indiana University, South Bend, he is increasingly called upon to lecture about the benefits of cannabis in humans — especially the potential for weed as a weight loss aid.

"I'm becoming more of a believer all the time, the more data I see," says Clark, who has recently digressed from insects and published several reviews and commentaries on his new topic of interest. "There are some inconsistencies in the data, but I really have decided that the positive effects of at least moderate use strongly outweigh the negative effects, and the negative effects can be avoided by controlling dose and using other delivery methods."

Clark's latest commentary, published in the Journal of Drug Abuse, extolls "the beneficial effects of moderate, adult use" and claims the current discussion of the public health impact of cannabis use results in "a misleading perception of harm."

"Cannabis use counteracts two serious public health crises," he writes, "the obesity epidemic and the drug overdose epidemic, thereby providing a net improvement in public health."

He is quick to point out that he doesn't think cannabis is a "miracle drug," but if there's evidence that weed might boost weight loss, it could catapult the herb into a whole new stratosphere — and your patients will be clamoring for answers.

Delving further into Clark's theory turns up a lot of question marks. While there's definitely curiosity in the scientific community, there's also pushback.

"I am inherently skeptical of these ideas," says Steven Heymsfield, MD, president of The Obesity Society, who has been involved in developing other weight loss drugs that never made it to market.

But colleagues of Heymsfield at the Pennington Biomedical Research Center, which lists obesity at the forefront of its mission, believe otherwise.

"There is a promise that medical marijuana may be part of the solution to the obesity and diabetes epidemic," write the center's executive director, John Kirwan, PhD, and chief medical officer, Frank Greenway, MD, in a recent editorial published in the International Journal of Obesity.

"I have a certain degree of reticence about marijuana because it hasn't been well studied," says Greenway, an endocrinologist. "But rather than just writing it off entirely I do think it's an appropriate subject to study."

As cannabis legally powers into mainstream culture across state and international borders, more scientists are starting to take notice. Canada is a new breeding ground. With cannabis federally legalized there last October, there's a flurry of scientific investigation — and excitement.

"Initially I had a student who started working on this; we did epidemiologic work but then he brought me the results," says Terence Bukong, PhD, a hepatology and infectious disease researcher at Montreal's Institut Armand-Frappier Research Centre, part of the University of Quebec's National Institute of Scientific Research. "I was amazed and said there might be something here."

After publishing studies about cannabis users who appear to be protected from various forms of liver disease, Bukong has now moved from observation to investigation in the lab. "What we're seeing in the context of epidemiologic reports we are also mirroring in the context of in vitro cell lines and mouse models," he says. "Our preliminary results show that specific formulations [of cannabis] actually enhance fat-burning while others enhance fat buildup."