According to In Style magazine, they recommend a 3-pronged dietary, exercise and wellness approach to firming your body skin:
Eating: blueberries, broccoli, pomegranates, green tea and 1,000 milligrams of pharmaceutical grade fish oil each day. Don’t eat fruit juice and white bread.
Exercise: keep cortisol/stress levels at bay with low key exercise like yoga and meditation.
Sleep: get plenty of sleep.