Health food is food considered to be beneficial to health in ways that go beyond a normal healthy diet required for human nutrition. Because there is no precise, authoritative definition from regulatory agencies such as the U.S. Food and Drug Administration, different dietary practices can be considered healthy depending on context. Foods considered "healthy" may be natural foods, organic foods, whole foods, and sometimes dietary supplements. Such products are sold in health food stores or in the health/organic sections of supermarkets. "Health food" may also refer to functional food that designed to address specific health concerns, such as the prevention of disease. Additionally, "health food" is sometimes used in contrast with "junk food", which may be high in calories but has little other nutritional value.