The evaluation of involuntary weight loss

Obstetrician/gynecologists will commonly encounter patients complaining of weight loss. Involuntary weight loss (IWL) is defined as a decrease of at least 5% of body weight within 6 months in the absence of intentional dieting, diuretic therapies, or conditions known to cause weight disturbances. Causes of IWL include decreased intake, increased fluid- nutrient loss, and excess metabolic demand. A high index of suspicion must be maintained to identify young patients with eating disorders. Elderly patients are prone to nutritional deficiencies, social difficulties, and medication side effects. A rational approach to IWL consists of a history, physical examination, and select screening laboratory examinations. If the cause of the weight loss remains unknown, a short observation time is reasonable. Undirected tests have low yield and are not recommended. The prognoses of patients with IWL are generally good. Therapy consists of nutritional supplementation, dietary counseling, treating the underlying cause, and addressing patient anxiety. Medications such as megestrol acetate may be prescribed to stimulate appetite. In one fourth of patients with IWL, no cause is found; the remaining 75% of patients have underlying cancers, nonmalignant diseases, or psychiatric disorders. Undiagnosed and untreated conditions can lead to significant morbidity and mortality. Therefore, as a primary care physician, the obstetrician/gynecologist must be skilled at the evaluation and treatment of involuntary weight loss.