Your body is your vessel in this life, not caring for it will lead to the breakdown of the mind and soul, it's all interconnected and cannot be ignored. How do we care for our body? Food is one way, what you eat directly affects your health, how can we better fuel ourselves? Put junk in your body & it will eventually breakdown, just like our cars, put the lower grade gasoline in an engine designed for premium and watch how the performance diminishes.
Exercise is another critical compenent to keeping the whole system working properly. Same analogy as the car, if you keep it covered and never start it or drive it around, it will eventually stop working.
These aren't complicated concepts and a few changes could provide you with an amazingly positive response from your body.