Although the drug is far from becoming a miracle pill for the treatment of obesity, is very promising as a solution to lose weight, at least in mice, researchers say.

The drug acts in the intestine and mimics the physiological processes that occur after an animal has eaten, as a result, mice consumed calories to make room for the "imaginary calories" that have ingested.

The drug, fexaramina enable a molecular switch which releases bile acids into the intestine in response to food. Normally, the job of bile is to help the body digest food, but its secretion into the intestine also has a ripple effect, it activates a number of processes throughout the body.

The new drug also appears to have fewer side effects than other similar drugs to lose weight because it stays in the gut, rather than enter the bloodstream and affect the whole body, according to the study.

Currently, people who are severely obese, even after trying to lose weight with diet and exercise, have very few treatment options, including gastric bypass surgery.

Now is the hardest, because the drug has to be tested in larger animals (primates) and then in humans, before being used as a treatment for obesity. This process could take a couple of years, according to researchers.

Ronald Evans, is the director of Salk's Gene Expression Laboratory and co-author of the article published on January 5, 2014 in the journal Nature Medicine.