Potatoes grow and thrive under the ground. This is a good thing. Couch potatoes, however, can also grow under the ground. This growth, generally horizontal about the middle, is not desirable. A healthy diet is important, along with some kind of regular exercise, even if it's just gardening and miscellaneous yard work, regardless of where we live.
Holesome living includes good nutrition and exercise for physical and mental well-being. Yoga and meditation are very effective, low-impact activities that can be done, to some degree, by nearly anyone, of any age. Regular massages by a licensed Massage Therapist are also invaluable for relieving stress and loosening up tight, sore muscles. The three make an excellent combination for a strong, flexible body and an alert, relaxed, and positive disposition.
As far as diets and nutrition go, there seems to be an opinion and a fad diet for about every dozen people on the planet. I've had pretty good luck with the old "burn more calories than you eat" plan. I don't shy away from "good" fats like butter and olive oil, but I don't go crazy, either. A little meat, some eggs, lots of veggies, fruits, nuts, berries and, of course, a smidgeon of ice cream (low fat). I think, as in all things, moderation is key. Your mileage may vary, especially if you have challenges such as diabetes, hypertension, etc. As always, consult your physician before starting any diet or exercise plan.