Eating Experiences and Behaviors after Metabolic Bariatric Surgery: A Multicenter, Longitudinal Study

Metabolic-bariatric surgery (MBS) often results in substantial changes of patients' eating behavior through physiological and behavioral mechanisms. However, its effects on different dimensions of eating, including eating in the absence of hunger (EAH), the subjective experience of eating (eating hedonics), and eating-related practices, remain insufficiently understood. This study examined longitudinal changes in these domains following MBS.

N=1058 patients (mean age 46.76, 68.20% female) undergoing Roux-en-Y gastric bypass or sleeve gastrectomy completed clinical interviews and questionnaires assessing EAH, eating hedonics, and eating-related practices pre-MBS, 6-, 12- and 24-months postoperatively. Item-level longitudinal changes were assessed using linear mixed-effects models. Standardized mean differences were calculated to estimate effect sizes. Longitudinal associations with percentage total weight loss (%TWL) were examined using adjusted linear mixed-effects models.

Descriptively, EAH decreased post-MBS, with the largest reductions for palatability-driven EAH. Eating hedonics showed very small to small changes, with increases in sensory enjoyment and decreases for negative affect during eating. Greater decreases in EAH were associated with 2.07 percentage-points higher %TWL, while changes in eating hedonics showed small, directionally mixed associations with %TWL. Compared to pre-MBS, some eating-related practices changed (e.g., increased chewing), whereas others (e.g., time spent on food preparation) remained largely unchanged.

Findings of reduced EAH, small but overall positive changes in eating hedonics and specific changes in eating-related practices contribute to a differentiated characterization of postoperative eating across multiple domains of eating. Longitudinal associations between EAH and weight loss highlight the importance of monitoring non-normative eating behaviors for optimizing postoperative outcomes.