India, Sept. 19 -- The worldwide overweight and obesity epidemic, and weight-related health complications such as diabetes and cardiovascular disease, have become critical healthcare issues in both developed and developing economies.

Much of the research focus to date has been on strategies to help people lose weight. However, very little is known about why certain people are resistant to weight gain in the first place. Understanding the biological mechanisms that underlie this resistance to weight gain can help in providing solutions that work on long-term weight and health maintenance.

Indeed, novel insights on metabolic differences in humans might come from studying very lean people, a state called Constitutional Thinness (CT). CT in...