Eating disorders are psychological illnesses defined by abnormal eating habits, that involve either insufficient or excessive food intake, to the detriment of a Pt's physical and mental health.

• Bulimia nervosa
• Anorexia nervosa
• Less commonly:
  • Binge eating disorder
  • OSFED (other specified feeding or eating disorder)

• Child abuse
• Social isolation
• Parental influence, and therefore familial genetic predisposition, dietary choices due to cultural/ethnic preferences, parents' own body shape and eating patterns, degree of involvement and expectations of their children's eating behavior, interpersonal relationship of parent and child
• Peer pressure, with studies showing 40% of 9-10yo girls are trying to lose weight
• Cultural pressure, with an emphasis on thinness especially pervasive in western society, and unrealistic stereotypes of beauty and ideal body type portrayed in media, fashion and entertainment

Thigh gap is a space between the inner thighs of women when standing upright with knees touching, and has become an aspect of physical attractiveness, fragility and feminity. It has led to extreme dieting, even surgery.

• Women in the Western world are at highest risk of developing eating disorders, and the degree of westernization increases the risk

• Bulimia
• Anorexia