*1.1. Punishment Sensitivity*

The most applied measures to assess sensitivity to punishment (BIS) and reward (BAS) are the BISBAS scales [21] and the sensitivity to punishment and sensitivity to reward questionnaire (SPSRQ) [22], both based on the original RST theory. The BISBAS scales focus on the general disposition towards reward (e.g., "When I'm doing well, I love to keep at it.") and punishment, whereas the SPSRQ items often include specific situational triggers related to punishment and reward (e.g., "Do you often meet people that you find physically attractive?"). Patients with EDs (AN-R, AN-BP, or BN) typically report significantly higher scores on punishment sensitivity (BIS/SP) compared to healthy controls [8,23–29]. When comparing different ED subtypes, most studies did not find significant differences among AN-R, AN-BP, or BN patients [8,25,29,30]. Two studies [23,27] showed that AN-R patients scored significantly higher on sensitivity to punishment than AN-BP or ED-PB (AN-BP + BN) patients, whereas other studies found the opposite [24] or no significant differences [31].

Studies comparing patients with obesity to healthy controls on punishment sensitivity are rather scarce. Class I obese patients without BED scored significantly lower on punishment sensitivity compared to healthy controls [32], whereas Class I obese patients with BED did not significantly differ from healthy controls [33]. Class II obese patients with and without BED scored significantly higher on punishment sensitivity than healthy controls [32,34]. No study has compared patients with Class III obesity with and without BED to healthy controls with respect to punishment sensitivity. When comparing obese patients (Class II, III) with and without BED on punishment sensitivity, patients with and without BED did not differ from each other [6,34]; no studies were performed in Class I obese patients with and without BED.

Higher punishment sensitivity in patients with EDs, as compared to healthy controls, seems to be linked to their symptomatology. Patients with AN-R relate their self-worth to their weight [35] and are afraid of gaining weight; their strict dieting can be considered as a way to avoid anxiety for weight gain [7,8]. Several studies have demonstrated a positive association between sensitivity to punishment and restrained eating in both adolescents and young adults [20,36]. Patients with binge eating (AN-BP, BN) and obesity, on the contrary, often use food to comfort or soothe themselves and to escape from negative feelings [37]. Davis [38], for example, showed a positive association between sensitivity to punishment and the symptoms of binge eating. The compensatory behaviors of patients with AN-BP/BN can again be considered as a way to avoid weight gain [7,8].
