The main ingredient in chili peppers could become a hot new diet supplement due to its ability to boost a sluggish metabolism, according to a research team at the University of Wyoming in the US.

They say diet supplementation with capsaicin -- the component of chili peppers that leads to weight loss -- could eliminate the need to restrict calorie intake.

It works by turning "bad" white fat into "good" brown fat, say the researchers, who presented their paper at the Biophysical Society's 59th Annual Meeting in Baltimore, Maryland in the US, which began February 7 and will continue until Wednesday.

"In our bodies, white fat cells store energy and brown fat cells serve as thermogenic (heat produced by burning fat) machinery to burn stored fat," says study author Vivek Krishnan, a UW graduate student.

Krishnan says capsaicin as a dietary supplement suppresses the weight gain that comes from eating rich foods by maximizing the presence of brown fat, whose thermogenic capabilities work to burn fat even without exercise.

Several studies have suggested that white and brown fat are capable of converting into each other -- often by means of temperature change -- and the current study indicates that capsaicin induces the browning of white fat.

Working with mice that were fed a high-fat diet topped off by a small (0.01 percent) serving of capsaicin, Krishnan and his team found the mice did not gain weight as expected because metabolic activity had quickened.

This was the case for all mice except those who genetically lacked a receptor for capsaicin and vanilloid called TrpV1.

The team is at work to develop a natural dietary supplement using capsaicin for combatting obesity and its members are highly optimistic that clinical trials will start soon with few roadblocks.

The researchers have already submitted a patent application for their method of delivering capsaicin in the body.