Core Pathology of Eating Disorders Eating disorders are cognitive disorders. It is essentially the over‐evaluation of shape and weight and their control. Whereas the majority of people evaluate themselves on the basis of their perceived performance in a variety of domains of life, people with eating disorders judge their self‐worth largely in terms of their shape and weight and control of them. This results in sustained and extreme attempts to limit food intake (dietary restraint). Some over‐exercise.  Bulimia Nervosa: The core of this is the dysfunctional scheme for self‐evaluation. They have strict dietary rules and when they break them at all they give up and just binge eat (abstinence violation effect). These binges often occur in reaction to stressors or negative moods as eating can reduce negative moods. They also think purging eliminates what they have eaten but it only gets rid of some and laxatives do nothing.  Anorexia differs from bulimia only in that the anorexic is more successful at restraining diet. Understanding Weight Checking Behavior I. Weight fluctuates normally throughout the day  You need to learn how to interpret the number you obtain when you weigh yourself. The number on the scale fluctuates through the day, and from day to day, according to your state of hydration, the state of your bowels and bladder, your point in the menstrual cycle and other factors. Frequent weighing results in preoccupation with inconsequential fluctuations in the number on the scale and these tend to be misinterpreted. II. Weight Checking always reinforces dieting  Draw a wiggly line showing normal fluctuations. Find a part that is a gain and extend it upwards showing that patients who see this think they will keep gaining weight so persist in dieting. Find a part that is stable and show how patients think they must try harder to diet. Find a part that shows weight loss and extend it downwards showing how patients think it's working so they have to diet even more. No matter what's on the scale the end result is dietary restraint. Normal Weight Fluctuations through the day III. For a Realistic View of Your Weight Check Your BMI You need to know that body weight is under strong physiological control and is difficult to influence in the long‐term. The BMI is weight (in kg) divided by height squared (in m) (Wt/Ht2). Significantly underweight‐ 17.5 or below Underweight‐ 17.6‐18.9 Low weight‐ 19‐19.9 Healthy weight‐ 20‐24.9 (Somewhat) overweight 25‐29 (Significantly overweight) obesity 30 or more IV. Weight Fluctuates 6 pounds throughout the Day  It is normal and healthy for your weight to fluctuate approximately 6 pounds in magnitude throughout the day. V. Your Weight is largely genetically determined  See the information sheet on “Set‐point theory”