One of the selling points of the prescription diabetes medication Invokana (canagliflozin) has been its role in helping patients shed excess pounds. However, a new study from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDKD) has found that it only works for weight loss for so long – and has the unfortunate effect of increasing a person’s appetite.

The NIDDKD study involved 242 subjects for a year. All patients were Type 2 (adult onset) diabetics who were able to eat and drink without any dietary restrictions. 153 of the patients were on Invokana, while 89 were given a placebo. Invokana, a “sodium-glucose transport inhibitor,” causes the patient to excrete excess blood sugar through the urine. That excess sugar translates into calorie loss, which resulted in those patients losing an average of eight pounds. But here is the rub: for every one of those pounds the Invokana patients were able to shed, they wound up eating approximately 50 more calories per day than they had been prior to their participation in the study.

In essence, the loss of those calories that were passed in the urine along with excess blood sugar caused a corresponding increase in patients’ appetites. In the end, the rate of weight loss slowed dramatically after six months, and eventually leveled off. Meanwhile, the 89 patients who received placebos also lost weight – but did not wind up consuming more calories. The results of the study were consistent with those from another clinical trial involving a commercial weight loss program in which subjects did not take Invokana. In that trial, patient’s weight loss efforts were offset by an increase in appetite and a gradual increase in caloric intake that resulted in a weight loss plateau.

Weight loss is a balancing act. What causes appetite is a depletion of nutrients, primarily glucose. Anyone who has used cannabis and wound up getting “the munchies” understand this, as THC, the active ingredient in cannabis, absorbs glucose in the bloodstream. In fact, there is scientific evidence that the use of medical marijuana is effective in controlling blood sugar levels and decreasing insulin resistance in patients with Type 2 diabetes. In light of that knowledge, it should not be surprising that patients taking canagliflozin would also be getting “the munchies,” since they are also losing glucose – in this case, through the urine.

The NIDDKD researchers concluded that, while Invokana may work as a weight loss aid for a time, over the long run, it can be counter-productive by increasing a patient’s craving for food. And of course, patients taking Invokana run the risk of ketoacidosis (excess acid in the blood) and kidney failure (which is not a danger with medical cannabis). It appears that claims of Invokana’s effectiveness as a weight loss aid are at best, overblown. The only reliable way to lose excess weight – which can go a long way toward managing diabetes – is by changing one’s diet and increasing physical activity.

K.J. McElrath is a former history and social studies teacher who has long maintained a keen interest in legal and social issues. In addition to writing for The Ring of Fire, he is the author of two published novels: Tamanous Cooley, a darkly comic environmental twist on Dante's Inferno, and The Missionary's Wife, a story of the conflict between human nature and fundamentalist religious dogma. When not engaged in journalistic or literary pursuits, K.J. works as an entertainer and film composer.