Known as exercise mimetics, this proposed class of drugs essentially 'mimics' the benefits of exercise, triggering a mechanism that supercharges fat metabolism and encourages lean muscle mass.

"This compound is basically telling skeletal muscle to make the same changes you see during endurance training," said lead author Thomas Burris, professor of pharmacy at the University of Florida.

While exercise mimetics have been in the works for some time, the UF researchers found that a compound known as SLU-PP-332 was able to target a specific estrogen-related receptor (ERR), which boosted skeletal fat oxidation, therefore increasing energy expenditure.

In a mouse study, SLU-PP-332 'revved' up a natural metabolic pathway that is normally excited through physical exercise. Compared to a control group of obese mice, the cohort given SLU-PP-332 twice a day for a month gained 10 times less fat and also lost 12% of their body weight in the process, with no changes to diet and exercise.

"They use more energy just living," Burris said.

The mice were also able to run nearly 50% further than prior to treatment, which supports previous research into how it strengthens the heart muscle.

"When you treat mice with the drug, you can see that their whole body metabolism turns to using fatty acids, which is very similar to what people use when they are fasting or exercising," Burris added. "And the animals start losing weight."

The class of drugs is very different to the emerging weight-loss medicines such as semaglutide, which drastically slow down digestion. However, this could potentially be complementary, since rapid weight loss can also result in a loss of lean muscle.