*1.4. The Present Study*

The aim of the present study is to investigate temperamental differences on BIS/BAS and effortful control along the ED/obesity spectrum. We collected data from female AN-R, AN-BP, and BN patients, healthy controls, and Class II and Class III obese bariatric patients with and without binge eating within the age range 18–65. Thus, we add to the existing literature by comparing ED, healthy controls, and obesity patients in one study on both executive/top-down and reactivity measures of temperament.

With respect to punishment sensitivity (BIS), we expect that ED and obese patients will score significantly higher compared to healthy controls. Within the ED/obesity subtypes, we do not expect significant differences on punishment sensitivity [48,49].

With respect to reward sensitivity (BAS), we expect no significant differences between ED and healthy controls, with the exception of a potentially lower reward reactivity in AN-R patients compared to healthy controls [48,49]. However, we do expect higher levels of reward sensitivity in obese patients compared to healthy controls. Within obesity subtypes with and without BED, we again do not anticipate differences in BAS reactivity [6,47].

Finally, concerning top-down control, we expect that patients with ED/obesity will score significantly lower than healthy controls [6,23,31,47], whereas patients with binge eating and/or purging (AN-BP, BN, obesity Class II/III with binge eating), are hypothesized to score lower on effortful control compared to patients without binge eating and/or purging (AN-R, obesity Class II/III without binge eating) [6,23,31].
