You are what you eat applies to more than physical fitness. "The Food-Mood Connection: Nutritional and Environmental Approaches to Mental Health and Physical Wellbeing" is a book discussing the possibility that many mental disorders are strongly affected by what the afflicted eat in their day to day lives. Explaining that the nutrition and chemicals brought into the body cause many different reactions and changes throughout, it's a theory based in science and applicable to one's everyday life. "The Food-Mood Connection" is something to consider when trying to increase one's overall mental and physical health.