Implications of nutritional status on human biochemistry, physiology, and health.

Optimum nutrition is the level of intake that should promote the highest level of health. Although excess caloric intake will lead to obesity, a deficit in nutrition may result in a tissue depletion of essential nutrients that can lead to biochemical changes and eventually to clinical signs and symptoms. Nutrition requirements may differ according to sex, age, activity, or physiological state and can be influenced by drugs, smoking, alcohol, and other factors. With ever-increasing sedentary life styles and less physically demanding jobs, the resulting reduced caloric requirements have made it more difficult to make nutritionally sound food choices. Nutrition is the single most important component of preventive health care. Diet has been associated with cancer, heart disease, diabetes, stroke and hypertension, arteriosclerosis, and cirrhosis of the liver. The ability of the human to respond to stresses, such as altitude, heat, trauma, surgery, and infection can be influenced by nutritional status. Nutritional status is reflected in a variety of metabolic processes that provide the basis for a number of methods for its assessment.