"Starvation results from inadequate intake of macronutrients (proteins, fats and carbohydrates). It may be partial or complete. In fasting, all food energy is excluded, whereas in semi-starvation insufficient energy and protein are ingested. Human starvation and semi-starvation result from deprivation of food, not specific nutrients, so both micronutrient and macronutrient deficiencies result, causing clinical disease. The body defends against these deficiencies by triggering hunger, a cognitive state in which there is motivation to eat food. Preliminary results of the long-term effects of semi-starvation were presented at the 9th International Congress on Eating Disorders, held in New York City on May 4-7, 2000.1 Elke Eckert and Scott Crow presented details from the landmark study of Ancel Keys, carried out at the University of Minnesota in the 1930s, and a 50-year follow-up of most of the volunteers alive today. Keys wanted to establish the best way of refeeding people who had starved in Europe as a result of World War II. One hundred men volunteered for his study, in which the effects of a 24-week period of semi-starvation were examined. All of the men had been screened for exceptional physical and psychological health. Of the 40 chosen, 4 dropped out because they could not tolerate semi-starvation: 3 developed binge-eating, 2 began to steal food, 1 suffered severe depression, and 2 were admitted to hospital because of symptoms of psychosis. In the 50-year follow-up, abnormal eating behaviours (although less severe than those just described) and ruminations persisted in all of the 25 volunteers who consented to interview. Eckert and Crow concluded that the effects of hunger are powerful and long-lasting."