Regarding exercise, resistance (weight) training is very important, especially as we get older. Very simply, muscle burns calories at rest, more muscle burns more calories at rest.

One of the main reason dieting doesn't work is when someone goes on a calorie restricted diet, they lose fat and lean muscle mass. When they drop the diet and gain the weight back, they're actually fatter at the same weight.

I highly recommend anyone concerned with fitness to view this website:

http://www.hussmanfitness.org/

It's like Fitness for Dummies and makes it easy to wade through all the garbage information that's out there.