 Nutrition, nutrition is the science that interprets the interaction of nutrients and other substances in food in relation to maintenance, growth, reproduction, health and disease of an organism. It includes food intake, absorption, assimilation, biosynthesis, catabolism, and excretion. The diet of an organism is what it eats, which is largely determined by the availability and palatability of foods. For humans, the healthy diet includes preparation of food and storage methods that preserve nutrients from oxidation, keep or leaching, and that reduce risk of food-borne illnesses. In humans, an unhealthy diet can cause deficiency-related diseases such as blindness, anemia, scurvey, preterm birth, stillbirth and creatinism, your nutrient-excess health-threatening conditions such as obesity and metabolic syndrome, and such common chronic systemic diseases as cardiovascular disease, diabetes, and osteoporosis. Under nutrition can lead to wasting in acute cases, and the stunting of marasmas in chronic cases of malnutrition.