Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, is the first of four Science Objects in the Nutrition SciPack. It demonstrates that all living organisms require food for functioning, renewal, and growth. Animals use both plants and other animals as food. Food provides the necessary energy for bodily movement and physiological processes. It also provides substances needed to repair and create bodily structures and regulate physiological processes such as cellular activity or immune responses. Nutrients, the substances and elements in food that the body requires, are classified according to their composition. For humans, these nutrients include carbohydrates, proteins, fats, vitamins, minerals, and water. Carbohydrates, fats, and protein are present in foods in larger amounts. Vitamins and minerals are present in only small amounts. Water, an essential nutrient, is part of every body cell and contributes to all physiological processes.