Reward-related gustatory and psychometric predictors of weight loss following bariatric surgery: a multicenter cohort study.

Reward sensitivity has been proposed as a potential mediator of outcomes for bariatric surgery. We aimed to determine whether gustatory and psychometric measures of reward-related feeding are predictors of bariatric-induced weight loss. A multicenter longitudinal cohort study was conducted in patients scheduled for bariatric surgery (surgical group), assessed at baseline and 2 follow-up assessments. Predictions of % weight loss from baseline (%WL) according to baseline gustatory measures, including intensity and pleasantness ratings of sweet and other tastants, and psychometric measures of reward-related feeding behavior, including hedonic hunger scores, were assessed with multivariable linear regression. Exploratory analyses were conducted to test for associations between %WL and changes in gustatory and psychophysical measures, as well as for comparisons with data from patients on the surgery waiting list (control group). We included 212 patients, of whom 96 in the surgical group and 50 in the control group were prospectively assessed. The groups were similar at baseline and, as expected, bariatric surgery resulted in higher %WL (BTreatment-Time  = 2.4; 95% CI: 2.1-2.8; P  < 0.0001). While variation in gustatory measures did not differ between groups, in the surgery group baseline sweet intensity predicted %WL at the primary endpoint (11 to 18 months postoperatively; β = 0.2; B = 0.2, 95% CI: 0.02 to 0.3; P  = 0.02), as did hedonic hunger scores (β = -0.2; B = -2.0, 95% CI: -3.8 to -0.3; P  = 0.02). Furthermore, at this endpoint, postsurgical reduction of sweet taste intensity and acceptance of sweet foods were associated with %WL (β = -0.3; B = -3.5, 95% CI: -5.8 to -1.3; P  = 0.003, and β = -0.2; B = -4.7, 95% CI: -8.5 to -0.8; P  = 0.02, respectively). The use of sweet intensity as a predictor of weight change was confirmed in another bariatric cohort. Sweet intensity ratings and hedonic hunger scores predict %WL after surgery. The variability of sweet intensity ratings is also associated with %WL, further suggesting they may reflect physiological processes that are variably modulated by bariatric surgery, influencing clinical outcomes.

Ribeiro G ，Camacho M ，Fernandes AB ，Cotovio G ，Torres S ，Oliveira-Maia AJ ... -  《-》

Enhanced sweet taste perception in obesity: Joint analysis of gustatory data from multiple studies.

While sweet taste perception is a potential determinant of feeding behavior in obesity, the supporting evidence is inconsistent and is typically associated with methodological limitations. Notably, possible associations between sweet taste perception and measures of food reward remain undetermined. We conducted a cross-sectional analysis comparing 246 individuals with severe obesity and 174 healthy volunteers using a validated method for taste perception assessment. We included gustatory variables, namely intensity and pleasantness ratings of sour, salt, sweet, and bitter tastants, and taste thresholds assessed by electrogustometry. Reward-related feeding behavior, including hedonic hunger, food addiction, feeding behavior traits, and acceptance of foods and alcohol, was evaluated using self-rated scales for comparison with gustatory measures. In logistic regressions adjusted for age, gender, educational level, and research center, we found that a greater likelihood of belonging to the obesity group was associated with higher sweet intensity ratings (OR = 1.4, P = 0.01), hedonic hunger, food addiction symptoms, restrained and emotional eating (1.7 < OR ≤ 4.6, all P ≤ 0.001), and lower alcohol acceptance (OR = 0.6, P = 0.0002). Using principal component analysis, we found that while hedonic hunger, food addiction, and emotional eating were strongly interrelated, they were not associated with sweet intensity perception that, in turn, had a closer relationship with alcohol acceptance and restrained eating. We found that individuals with obesity report higher sweet taste intensity ratings than healthy controls. Furthermore, while psychological measures of reward-related feeding behavior assess a common construct, sweet intensity perception may represent a different obesity-related dimension.

Ribeiro G ，Torres S ，Fernandes AB ，Camacho M ，Branco TL ，Martins SS ，Raimundo A ，Oliveira-Maia AJ ，Food Reward in Bariatric Surgery Portuguese Study Group ... -  《Frontiers in Nutrition》

Hedonic hunger, eating behavior, and food reward and preferences 1 year after initial weight loss by diet or bariatric surgery.

The objective of this study was to investigate changes in hedonic hunger, eating behavior, and food reward and preferences at 1-year (1Y) follow-up after an initial weight loss (WL) induced by a 10-week, very low-energy diet alone (controls) or in combination with bariatric surgery. Patients scheduled for sleeve gastrectomy or Roux-en-Y gastric bypass and controls were recruited. Body weight/composition, hedonic hunger (Power of Food Scale), eating behavior traits (Dutch Eating Behavior Questionnaire and Three-Factor Eating Questionnaire), and food reward and preferences (computerized behavioral task) were measured at baseline, 11 weeks, and 1Y follow-up. Changes in anthropometric variables were comparable across groups in the initial phase (week 11), and hedonic hunger decreased overall. The bariatric-surgery groups continued to lose body weight and fat mass, whereas weight regain was seen in controls at 1Y follow-up. Decreases in emotional eating, hunger, disinhibition, and food reward and increases in dietary restraint were seen at 1Y follow-up in the bariatric-surgery groups only. Continued WL with bariatric surgery is paralleled by favorable changes in eating behavior and food reward and preferences. By contrast, controls experienced weight regain at 1Y follow-up and no changes in eating behavior. These striking differences are likely to be important in the long-term WL management of individuals with severe obesity.

Aukan MI ，Finlayson G ，Martins C 《-》

Neural processing of sweet taste in reward regions is reduced following bariatric surgery.

Bariatric surgery reduces sweet-liking, but mechanisms remain unclear. We examined related brain responses. A total of 24 nondiabetic bariatric surgery and 21 control participants with normal weight to overweight were recruited for an observational controlled cohort study. They underwent sucrose taste testing outside the scanner followed by stimulation with 0.40M and 0.10M sucrose compared with water during functional magnetic resonance imaging. A total of 21 bariatric participants repeated these procedures after surgery. Perceived sweet intensity was not different among the control, presurgery, or postsurgery groups. Bariatric participants' preferred sweet concentration decreased after surgery (0.52M to 0.29M; p = 0.008). Brain reward system (ventral tegmental area, ventral striatum, and orbitofrontal cortex) region of interest analysis showed that 0.40M sucrose activation  (but not 0.10M) decreased after surgery. Sensory region (primary somatosensory and primary taste cortex) 0.40M sucrose activation was unchanged by surgery and did not differ between control and bariatric participants. Primary taste cortex activation to 0.10M sucrose solution was greater in postsurgical bariatric participants compared with control participants. Bariatric surgery reduces the reward system response to sweet taste in women with obesity without affecting activity in sensory regions, which is consistent with reduced drive to consume sweet foods.

Alessi J ，Dzemidzic M ，Harezlak J ，Kareken DA ，Considine RV ... -  《-》

Effect of a 10-month residential multidisciplinary weight loss intervention on food reward in adolescents with obesity.

While multidisciplinary weight loss (WL) programs have been suggested to improve the sensitivity of appetite control system, this study examined for the first time the effect of a specific multidisciplinary intervention on the hedonic aspects of food intake in adolescents with obesity. Twenty-four adolescents (11-15 years) with obesity (mean BMI: 35.7 ± 4.5 kg/m2; BMI percentile: 98.7 ± 0.5) took part in a 10-month inpatient WL program, which included physical activity, nutritional education and psychological support. Height, weight, body composition, food reward (pre- and post-meal), ad libitum energy intake, appetite sensations and eating behavior traits were assessed at baseline, 5 months and at the end of the 10-month intervention. Analyses were conducted with linear mixed models and paired t-tests. The mean WL was 8.9 ± 6.9 kg. Appetite sensations and pre-meal hedonic ratings of liking for all food categories (HF: high-fat; LF: low-fat; SA: savory; SW: sweet) increased after 5 months (fasting hunger, p = 0.02; fasting desire to eat, p = 0.01; daily hunger, p = 0.001; pre-meal liking for HFSA, p = 0.03; LFSA, p = 0.04; HFSW, p = 0.009; LFSW, p = 0.005). In contrast, appetite sensations (fasting and daily), emotional eating (p < 0.001), uncontrolled eating (p = 0.009), and pre-meal explicit liking (for all food categories) decreased between months 5 and 10. Post-meal liking for HFSA (p < 0.001), LFSA (p = 0.002), HFSW (p = 0.02) and LFSW (p < 0.001) decreased between baseline and month 5 and remained unchanged between months 5 and 10. These findings suggest that adaptive mechanisms to WL occurring in the short-to-medium term are attenuated in the longer term with the persistence of WL. These results indicate improvements in the reward response to food in adolescents with obesity and may contribute to the beneficial effect of multicomponent WL interventions in this population. Future studies are required to confirm these findings and elucidate underlying mechanisms.

Miguet M ，Beaulieu K ，Fillon A ，Khammassi M ，Masurier J ，Lambert C ，Duclos M ，Boirie Y ，Finlayson G ，Thivel D ... -  《-》