COGNITIVE PROCESSES AND BIASES
Patients with eating disorders typically have irrational cognitions concerning their appearance, body and weight. They find themselves too fat and this is an irrational belief as, objectively, patients with either anorexia nervosa or bulimia nervosa are not overweight. Such irrational cognitions fuel excessive dieting, which may be the reason that challenging these cognitions appears to be beneficial in the treatment of eating disorders.
Cognitions, dieting and overeating
According to some researchers, dieters have a so called diet boundary: “I can eat this much, but certainly not more”. Crossing this diet boundary will evoke disinhibiting thoughts: “I ruined my diet, so I may just as well continue eating”. This what the hell effect thus explains overeating as for example in eating binges.
When instructed to taste and evaluate ice cream in a taste test, one will usually eat less ice cream when one has had one or two milkshakes to drink just prior to the taste test. This, however, is not what dieters do. Dieters who received a preload just before taking part in a taste test eat as much ice cream as (or even more than) dieters who did not get a preload prior to the taste test do. Such counterregulatory eating can be viewed as a model for an eating binge and can be readily explained in terms of the what the hell effect. Our own research on this topic however, shows that the dieters’ failure to regulate eating behaviour is not associated with any specific disinhibiting cognition. Furthermore, dieters (or rather restrained eaters) also demonstrate the failure to regulate their eating when they merely had to smell at food prior to a taste test. This, of course, does not mean that disinhibiting cognitions do not play any role in overeating, but it does imply that these cognitions are not a prerequisite for and as such not the primary cause of overeating.