Food provides nutrients that serve various functions in the body. It provides energy through oxidation, supports growth and cell formation, replaces broken cells, maintains metabolism, fights disease, and regulates homeostasis. To be nutritious, food must contain carbohydrates, fat, protein, vitamins, minerals, and water in balanced amounts. It also needs to be easy to digest and hygienic by being free of disease and dangerous substances. Nutrients can be categorized into micronutrients like vitamins, minerals, and water, and macronutrients such as proteins, lipids, and carbohydrates.