Q: Since muscle weighs more than fat shouldnt people lose weight as they get older and not the reverse? A person who watches what they eat and who exercises should lose weight as they enter into their sixties ad seventies.

A: Some older people actually do manage to keep their weight constant or even lose some of it as they age, mainly, as you said, through exercise and watching their diet. However it is not common. Losing muscle with age (into 50s and beyond) is virtually unavoidable because of the way our systems function. That loss of muscle mass and other changes in the body as the person ages lead to much lower metabolism which means that the body now stores fat much more readily. In addition the daily activity level typically decreases significantly with age, so fewer calories are burnt there as well. Plus few older people maintain a regular exercise routine and fewer yet participate in weight training.

What's really unfortunate is that many old people accept this situation as inevitable, while the truth is that regular exercise (both weight training and cardio) can add many quality years to their lives. Moderate weight training in the later years preserves muscle mass, raises metabolism, gives energy, and improves strength and bone density helping prevent bone breaks and fractures so common among older people. Cardio training helps prevent cardiovascular disease which is the #1 killer in the Western world. Both types of training and a healthy diet help prevent many forms of cancer, the #2 killer. If anything, being fit carries more benefits for the older people compared to the young!