1. A large number of studies confirm a consistently positive relationship between physical fitness and health. 2. A balanced diet can lift one's mood - give more energy - feed muscles - improve circulation - prevent illness - strengthen the immune system and make one feel betterto cope with stresses of life. 3. The key to healthy living is to eat three main meals a day - and eat a varied well-balanced diet. 4. How much nutrition one needs depends on one's activity level - genetic make-up - climate - and health history. 5. What people eat - and how much do they weigh involve behavioural processes