I would say I'm fairly healthy for my age, probably due more to the type of work I do than to personal habits. During the spring up until winter I strap on about 50lbs. of GPS equip, tool belt, hammer, big bag full of grade stakes and walk anywhere from 1 to 5 mi. on an average day. Then winter rolls around and if/when I'm laid off I eat too much(I love meat,btw), gain weight, 10-15 lbs., and spend more time playing guitar than working out. I, too, enjoy my beer, sure that doesn't help. We have a treadmill and weight set, I must ashamedly admit I don't use them in a regular, regimented routine, however.
More like when I begin feeling sluggish, blah, I know it's time to get moving and do something about it.
I notice a big difference when spring rolls around and I'm constantly on the move and working all the major muscle groups daily. People who workout or get regular exercise in any manner are generally more upbeat, positive, happy, and have more energy, myself included. (Sorry, couch potatoes, it's a fact. I know 'cause I'm usually a couch potato myself 1 or 2 months a year.)
Simple stretching exercises, done regularly, will also make a difference in the way I feel (for the better). That said, I know diet and exercise make the difference, I'm just never ready to do the diet part, but I will exercise when I need to. And if I listen to the "experts (doctors)" opinions, I have good heart rate, slightly high blood pressure, good lung capacity, flexibility, muscle mass, slightly elevated cholesterol, and I'm in good shape for 52yrs. of age.
BTW, I also believe in a positive outlook. People who find inner peace (and I'm not saying I'm there yet, I'm working towards that goal) cope much better in chaotic, unpleasant situations. That also is a health issue that needs to be taken into consideration.