Even if it does sound like a grade-school aphorism created to get kids to eat their vegetables, there`s a great deal of truth in the age-old saying, "You are what you eat." Consuming nutrient-rich foods such as spinach may not instantly result in bulging muscles like it does for Popeye, but we are quite literally made of the foods we consume. The vitamins and minerals in food are fundamental to the development of all the body`s tissues and fluids, and vital to the countless functions that keep our internal systems working.