As you get older, we learn from experience, or hopefully we do. An important truth that we come to understand from experience is the importance of finding and maintaining balance in our lives. It may be a cliché, but the old adage "Everything in moderation," is wise advice. When it comes to weight management, a little too much and you get sick, fat, or allergic. Too little, and you're deprived, empty, too skinny.
The best idea is to take the middle path. With food and eating, think quality not quantity. Have some of a lot of things, but not too much. It's important to get all of your vitamins and minerals, proteins, and fiber, but not too much or you'll gain weight. It's also important not to eat so little you rob yourself of nourishment. If you diet, then eventually you always feel deprived and end up going "off" your plan.
With exercise and movement, the middle path of balance is the best way as well. Exuberantly signing up for a health club membership and then overdoing it will only cause you to give up because it was too hard, too expensive. Jumping into advanced classes will wear you out fast and possibly injure you. Slow and easy, and consistent, is the balanced best way.