Components of nutrition include water, carbohydrates, proteins (including essential amino acids that cannot be synthesized by the body in sufficient quantities), fats, vitamins, trace elements and indigestible fibres. Disorders of nutrition include excessive caloric intake leading to obesity, eating disorders such as anorexia nervosa and bulimia nervosa and various malnutrition disorders.
Malnutrition disorders are often directly related to diet deficiencies in vitamins (structurally unrelated organic compounds), trace elements and minerals. Whilst disorders of malnutrition can be serious or life threatening, they can usually by corrected by supplementing the diet with the otherwise diet-deficient mineral. Therefore the pharmacology of obesity and eating disorders is discussed below.
Obesity
Obesity is caused by excessive caloric intake compared to energy expenditure over a prolonged period of time. The body mass index (BMI) is used to characterize individuals with a BMI >30.0 kg/m 2 ( Table 27.1 ). Obesity is an increasing worldwide problem; for example one in three adults in the United States is classified as obese (BMI >30.0 kg/m 2 ) and another one in three adults is classified as overweight (BMI 25.0–29.9 kg/m 2 ).
Undernutrition | Normal Weight | Overnutrition |
---|---|---|
Severe <15.9 kg/m 2 | Overweight 25.0-29.9 kg/m 2 | |
Moderate 16-16.9 kg/m 2 | 18.5-24.9 kg/m 2 | Obesity 30.0-39.9 kg/m 2 |
Mild 17.0-18.4 kg/m 2 | Morbid obesity >40.0 kg/m 2 |