An enormous chunk of people in America (one-third of the population), at this point, are overweight or obese. As obesity and its chronic complications continue to place a heavy burden on the health care system, researchers are trying to better understand the mechanisms behind it.

In a new study, researchers from the German Cancer Research Center examined how the physiological effects of obesity cause diseases, and how to potentially curb them. The authors of the study explain that obesity and its pathogenic changes (including type 2 diabetes and Metabolic Syndrome) can be traced back to chronic inflammation in fatty tissue. The fatty tissue — also referred to as adipose tissue — in obese people has much higher quantities of immune and inflammatory cells compared to people with normal weight.

“We are quite convinced that immune cells play a role in the pathogenic consequences of obesity,” Professor Hans-Reimer Rodewald, an author of the study, said in the press release. “But apart from that, little is understood so far about the exact processes that lead to disruptions in metabolism.”

That’s where a new twist comes in. Rodewald and his team pinpointed a particular enzyme found in immune cells that is responsible for triggering obesity’s negative effects on a person’s health. The enzyme is known simply as “Kit.”

Kit is found in blood, immune, and stem cells. Using mice for their study, the researchers tested weight gain in those that had a working Kit enzyme as well as those who had a Kit deficiency. When they fed all the mice a diet rich in fat, the mice who had a Kit deficiency were actually protected from weight gain, obesity, and metabolic disorders; but those whose Kit enzyme was functioning saw all the negative effects of poor eating.

“Now we know the key molecule involved in the development of pathogenesis,” Rodewald said in the press release. “But we still have to find out which of the various immune cell types are actually involved.”

Of course, the authors can’t claim that intervening with the Kit enzyme would work the same in humans. They’ll need to do further research to solidify their results, and to potentially one day develop an obesity therapy or drug that prevents weight gain.

Currently, there are some obesity drugs that impair dietary intake and absorption, as well as increase a person’s energy expenditure. But these drugs are meant to be used short-term; to lose weight and keep it off for good, overweight or obese people should adhere to a healthy, balanced diet and plenty of exercise.

Source: Gutierrez D, Muralidhar S, Feyerabend T, Herzig S, Rodewald H. Hematopoietic Kit Deficiency, rather than Lack of Mast Cells, Protects Mice from Obesity and Insulin Resistance. Cell Metabolism. 2015.