Anorexia Nervosa is one of the four types of eating disorders that are characterised by disturbances in thinking and behaviour around food, eating, and body weight and/or shape. Anorexia Nervosa is a serious psychological illness involving dangerously low body weight, whereby a person deprives themselves of food and may be engaging in excessive exercise in order to continually reduce body weight based on a false body image and a fear of becoming overweight/gaining weight.