The main chemical messengers that control the body functions are the hormones. Estrogen and testosterone are the main sex hormones in females and males, but there are many other hormones in our body which control its functions.
In order to maintain your health at higher level, you should know how hormones work. For instance, there are hormones that control hunger and weight loss and they are called insulin, leptin and cortisol. You can boost the hormones associeted with controlling hunger and losing weight by developing certain habits.