Anorexia nervosa (AN) is a serious mental illness, characterized by severe energy intake restriction, an intense fear of weight gain and an inability to maintain a healthy body weight. The individual will often experience severe body image dissatisfaction and distortion.

Bulimia nervosa is an eating disorder characterized by a cycle of binge eating episodes followed by purging episodes. with the association of extreme concerns over body shape and weight. In bulimia nervosa, a binge is defined as eating an unusually large amount of food in a short period of time, often within 2 hours, accompanied by a feeling of loss of control over eating.

Binge Eating Disorder (BED) is a serious mental illness characterized by recurrent episodes of binge eating followed by marked distress, guilt, shame and embarrassment. In contrast to bulimia nervosa, individuals with BED do not engage in compensatory behaviours such as restriction or purging. This can mean that people with BED tend to fall in the normal weight or overweight range.

ARFID is an eating or feeding disturbance characterized by a persistent failure to meet appropriate nutritional and/or energy needs. It is the second most common eating disorder in children 12 years and younger but largely under diagnosed.

OSFED stands for Other Specified Feeding or Eating Disorder. It describes eating problems that cause significant distress but don't fit neatly into criteria for other disorders like anorexia or bulimia.