The body manages its energy supply with amazing precision. Consider that many people maintain their weight within about a 10- to 20-pound range throughout their lives. How do they do this? How does the body manage excess energy? How do bones, muscle, fat, fluid, and other tissue influence our body composition? However, overweight, and underweight both result in energy imbalance. Almost 42% of adults aged 20 and above are overweight placing them at risk of developing chronic diseases that affect quality of life.