"You’re telling me things I already know, professor. My point about exercise is that many people just start exercising to lose weight and never do. Many studies out about that now. Exercise is not a weight-loss program by itself. Without a diet component you will just end up eating more, but you will have a healthier heavy body. And that leads us to the calories in/out mantra, which is what I preach to everyone."

Vigorous agreement. You threw me for a minute, there. True you can exercise more and not lose weight, but you can also eat less and not lose weight. (Most of my information comes from reading research not one-on-one conversations with doctors so the advice a particular doctor gives to a particular patient may vary.) The conventional wisdom is for most people 20 minutes of moderate exercise per day leads to much better overall health and mild weight loss. To get to more serious weight loss this needs to be upped to an hour a day which I admit is a bit much to fit into most peoples lives. The advantage of focusing on exercise rather than diet is that exercise can become an enjoyable part of one's life (listening to book tapes, walking the dog, walking the kids, walking the wife, walking by yourself without any dog, wife, or kids) and you don't have to feel hungry all the time. To lose weight by diet and keep it off you need a level of self-control that is unusual in the general population. You also miss out on all the benefits that exercise provides such as keeping your brain young.