Background: Second generation antipsychotics (SGA) induce substantial weight gain but the mechanisms responsible for this phenomenon remain speculative. Objective: To explore eating behaviors among SGA-treated patients and compare them with nonschizophrenic healthy sedentary individuals (controls). Methods and Procedures: Appetite sensations were recorded before and after a standardized breakfast using visual analog scales. Three hours after breakfast, a buffet-type meal was offered to participants to document spontaneous food intake and food preferences. Satiety quotients (SQs) were calculated to determine the satiation of both meals and the Three-Factor Eating Questionnaire (TFEQ) was used to document eating behaviors. Body composition and abdominal fat distribution were assessed. Results: Compared with controls (n = 20), SGA-treated patients (n = 18) showed greater adiposity indices (P ≤ 0.04). Patients' degree of hunger was also higher following the standardized breakfast (P = 0.03). Moreover, patients had significantly higher cognitive dietary restraint, disinhibition, and susceptibility to hunger scores than the reference group (P ≤ 0.05). Disinhibition in the reference group was positively associated with hunger triggered by external cues (r = 0.48, P = 0.03) whereas internal cues seem to mainly regulate emotional susceptibility to disinhibition in patients (r = 0.56, P = 0.02). Higher strategic restraint behavior in patients was associated with decreased satiation right after the buffet-type meal (r = −0.56, P = 0.02). Discussion: These exploratory findings suggest that patients under SGA seem to develop disordered eating behaviors in response to altered appetite sensations and increased susceptibility to hunger, a factor which may influence the extent of body weight gain triggered by these drugs.