How metabolism, genes and hormones affect weight

Much about how the body regulates appetite, metabolism, fat accumulation and other weight-related factors remains poorly understood. As rates of obesity and diabetes all over the world continue to climb, researchers are working to create new tools for managing your midsection. The following guidelines will tell you more.

Of course, the main principles of weight loss will always remain the same. To lose pounds, you need to burn more calories than you take in each day. But that's not as simple as it sounds. Many people find losing weight to be difficult because the body seems programmed to keep weight consistent; your metabolism might change over time to help this happen.

Researchers are trying to determine the underlying physiological reasons why many of us seemed to be locked into a weight that is above what would be considered healthy.

Another thing that has researchers' attention is the fact that fatness often runs in families. By some estimates, as much as 40 to 70 percent of such traits as body mass and fat formation in the gut are determined by your genes. Now that the human genome has been mapped, scientists are trying to zero in on the genes — and there are likely to be many — that contribute to weight control.

One exciting development was the discovery of a genetic defect that curbed production of a newly identified appetite-regulating hormone called leptin. Understanding leptin's effects on weight and how to manage leptin in the body could lead to breakthroughs in the future.

Researchers also are looking at clusters of genes on two chromosomes that may predispose people to abdominal fat and insulin resistance. The hope is to determine how the relevant genes interact with each other and eventually be able to custom-design drugs that can fix fat-affecting flaws in an individual's genetic makeup.