Researchers say they've identified a new hormone that by mimicking the effects of exercise can slow weight gain and guard against the development of diabetes.

The newly discovered hormone, MOTS-c, can fight the weight gains inherent in a typical high-fat Western diet and normalize the metabolism, benefits similar to what are provided by a regimen of physical exercise, they say.

The hormone chiefly targets muscle tissue, restoring insulin sensitivity to counteract diet-induced or age-dependent insulin resistance and allowing more effective processing of glucose sugars in the body, the researchers at the University of Southern California report in the journal Cell Metabolism.

"This represents a major advance in the identification of new treatments for age-related diseases such as diabetes," says study senior author Pinchas Cohen, dean of the university's Leonard Davis School of Gerontology.

Hormones are molecules that act as signals for the body to trigger certain physiological responses.

The researchers took mice that were fed a high-fat diet that usually causes them to become obese and develop resistance to insulin and injected them with the MOTS-c hormone.

They found that not only did the hormone suppress both outcomes -- obesity and insulin resistance -- in the mice, it was also able to reverse age-dependent insulin-resistance, a precondition often leading to diabetes.

MOTS-c is unique among hormones for being encoded in the DNA of mitochondria, parts of a cell that act as "powerplants" to convert food into energy, while other hormones are encoded in DNA found in the cell nucleus, the researchers point out.

"This discovery sheds new light on mitochondria and positions them as active regulators of metabolism," says study lead author Changhan Lee, and assistant professor at USC Davis.

While experiments with MOTS-c has to date been limited to mice, the molecular mechanisms that allow it to function in mice are present in all mammals, including humans, the researchers note.

Although further research into MOTS-c and its mechanisms is required, clinical trials on humans could begin in around 3 years, Cohen says.

Diabetes affects an estimated 380 million people worldwide, a figure expected to increase to almost 600 million by 2035.

Around 10 percent of those affected suffer from Type 1 diabetes, which requires insulin injections to control. Type 2 diabetes can often be treated with medications.

In the study, the USC researchers collaborated with the David Geffen School of Medicine at UCLA and the National Institutes of Health, which provided some of the funding for the research.