[NTF6]

Be wary of over gym use. I love the gym and have been bodybuilding since I was 19 (now 51) and tendonitis is a regular feature of my shoulders and elbows now. I recently had my left shoulder diagnosed with Reactive Calcification of the Sub-scapulars which I'm told will go away but has been very painful for 3 months and excruciating when it broke up and was re-absorbing the calcium. I have built over the years some very impressive muscle for my age but I'm always left wondering how much better my joints would be if I had never done weights.

I'd say hit the gym once a week for an all over body workout.
Go for a brisk walk (don't run or you'll end up with buggered joints...eventually) a few times a week (with your dog or your wife or your kids, or all of them)
Exercise portion control when you eat.
Avoid processed foods as much as possible.
Avoid fatty foods simply because you can eat more carbs and proteins if you do.
Limit high calorie alcohol consumption.