The study of how food nourishes the body: nutrients (protein, non-nutrients (antioxidants, phytochemicals (resveratrol, foods (fortified/enriched) Nutrition: the sum of all processes involved in the intake & utilization of food by living organisms. This includes digestion, absorption, transport, and metabolism of nutrients. Unlike a car, your body continuously renews itself. Food and the substances that make up food play a key role in health and functioning. The best food choices will support body"s growth and maintenance. Nutrient: a substance found in food that performs physiological or biological functions in the body. Examples: protein: development and function of muscle tissue, carbohydrate/fat: primary source of energy. Components of food that are indispensable to the body"s functioning. 4 are organic (contain carbon: carbohydrate, protein, fat, vitamins. 3 provide energy (contain calories: carbohydrates, protein, fat. Nutrient density: a measure of nutrients provided per kilocalorie of food. Empty calories: high in energy-yielding nutrients and low in non-energy yielding nutrients.