The main criteria necessary for the diagnosis of anorexia nervosa are:

  • Excessive weight loss or lack of normal weight gain, often to the point of starvation
  • Intense fear of gaining weight or becoming fat
  • Distorted image of body weight or shape
  • Absence of at least three menstrual periods in a row in females

These are common behaviors that occur in anorexia nervosa:

  • Significant reduction of the amount of food eaten
  • Avoiding eating; skipping meals
  • Intense focusing on food, eating, and body weight and shape
  • Repeatedly weighing oneself
  • Denial of hunger
  • Rigid eating patterns, such as extreme controlling of calories and fat even when underweight
  • Unusual rituals at mealtimes, such as cutting food into tiny pieces, moving food around the plate, and throwing out food so it does not have to be eaten
  • Storing or hoarding food
  • Collecting recipes and cooking for others while finding excuses to avoid eating
  • Wearing baggy clothes to hide the amount of weight lost
  • Obvious fear or anxiety before eating and guilt after eating
  • Complaining of bloating and unusual fullness after eating only small amounts of food
  • Excessive or compulsive exercising