Aging and Weight Gain

Using a mouse model, scientists have uncovered one reason why losing weight is so much more difficult for people as they age. We have both "brown" fat and "white" fat. Brown fat is very metabolically active and helps to burn white fat. As mice age, the brown fat as less metabolically active than it was when the mouse was younger. In humans, this could help account for the fact that we have to consume fewer calories and exercise more than when we were younger to even maintain the same body weight.