Anorexia nervosa: A condition where people avoid food, severely restrict food, or eat very small quantities of only certain foods.

Avoidant restrictive food intake disorder (ARFID): A condition where individuals limit the amount or type of food eaten.

Binge eating disorder: A condition where people lose control over their eating and have recurring episodes of eating unusually large amounts of food. Unlike bulimia nervosa, periods of binge eating are not followed by purging, excessive exercise, or fasting.

Binge eating episode: An episode characterized by both eating in a discrete period of time (e.g., within any two-hour period) an amount of food that is definitely larger than what most individuals would eat and a sense of a lack of control over eating during the episode.

Body mass index (BMI): A person’s weight in kilograms divided by the square of height in meters.

Bulimia nervosa: A condition where people have recurrent and frequent episodes of eating unusually large amounts of food and feeling a lack of control over these episodes.

Emaciation: A condition of extreme thinness.

Family-based therapy: A type of psychotherapy where parents of adolescents with anorexia nervosa assume responsibility for feeding their child.

Lanugo: Growth of fine hair all over the body.

Pica: An eating disorder in which an individual repeatedly eats things that are not considered food with no nutritional value, such as paper, dirt, soap, hair, glue, or chalk.

Purging: Behavior in eating disorders used to compensate for overeating, such as forced vomiting, excessive use of laxatives, or diuretics.

Refeeding syndrome: A potentially fatal complication for any client with negligible food intake for more than five days that involves hypophosphatemia; serious sodium and fluid imbalances; changes in glucose, protein, and fat metabolism; thiamine deficiency; hypokalemia; and hypomagnesaemia.