Washington: Excessive consumption of a fat-rich diet could be fuelling the obesity epidemic in the US and other parts of the world. But not all fats are equal.

While animal-origin saturated fats like lard and butter are strongly linked to adverse health effects, unsaturated and polyunsaturated fats from plants and cold-water fish like salmon and mackerel can reduce the risk of cardiovascular disease and diabetes and produce other health benefits, reports the journal Cell.

Biomedical investigators have been wondering why saturated and unsaturated fatty acids produce such diametrically opposite results.

Researchers from the University of California, San Diego School of Medicine have found the explanation that could lead to dietary supplements designed to treat obesity at the molecular level, according to a San Diego statement.

"These findings also provide improved tools and a mechanistic framework for the potential development of dietary supplements to treat obesity," said study author Michael Karin, professor of pharmacology at the college.