How does eating well and exercising increase my longevity?

How does eating well and exercising increase my longevity?

There are various ways to shorten one's lifespan and one of them is to put on too much weight. If one doesn't get enough exercise to keep a constant weight then lots of other things go wrong as a result of carrying around too much fat which causes hormonal changes in the blood which has effects on all of our various types of metabolic processes and generally destabilizes them and accelerates age-related problems, especially diabetes and or heart disease. And therefore getting enough exercises will stop that happening and it will not accelerate one's aging, but we can't take that too far unfortunately because there is a basal rate of accumulation of these various types of molecular and cellular damage which happens even if we're keeping a constant weight and if we're avoiding the other things that we all know we ought to avoid like smoking or not getting enough micronutrients or whatever.