Taste-related reward is associated with weight loss following bariatric surgery

Abstract

BACKGROUND. Bariatric surgeries are the most effective treatments for successful and sustained weight loss, but individuals vary in treatment response. Understanding the neurobiological and behavioral mechanisms accounting for this variation could lead to the development of personalized therapeutic approaches and improve treatment outcomes. The primary objectives of this study were to investigate changes in taste preferences and taste-induced brain responses after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) and to identify potential taste-related predictors of weight loss. METHODS.Females, ages 18 to 55, with a body mass index greater than or equal to 35 kg/m 2 , and approved for bariatric surgery at the Johns Hopkins Center for Bariatric Surgery were recruited for participation. Demographics, anthropometrics, liking ratings, and neural responses to varying concentrations of sucrose plus fat mixtures were assessed before and after surgery via visual analog scales and functional MRI. RESULTS.Bariatric surgery produced decreases in liking for sucrose-sweetened mixtures. Greater preference for sucrosesweetened mixtures before surgery was associated with greater weight loss in RYGB, but not VSG. In the RYGB group only, individuals who showed lower taste-induced activation in the ventral tegmental area (VTA) before surgery and greater changes in taste-induced VTA activation 2 weeks following surgery experienced increased weight loss. CONCLUSION.The anatomical and/or metabolic changes associated with RYGB may more effectively "reset" the neural processing of reward stimuli, thereby rescuing the blunted activation in the mesolimbic pathway found in patients with obesity. Further, these findings suggest that RYGB may be particularly effective in patients with a preference for sweet foods.

Phase-locking of resting-state brain networks with the gastric basal electrical rhythm

“…In the present study, we acquired fMRI data only in the “resting” state. Researchers have used fMRI to measure brain responses to hedonic/gustatory stimuli such as photographs of food [ 59 ] and the the ingestion of small samples (“sips”) of fluid delivered during scanning [ 60 , 61 ]. Concurrent EGG would allow future studies in this area to benefit from measures of how such stimuli affect the stomach’s rhythm, and stomach-brain synchronization.…”

tVNS Increases Liking of Orally Sampled Low-Fat Foods: A Pilot Study

“…However, it is also possible that the fixed order of non-fatty sweet Jell-O samples presentation after fatty puddings samples may have worked against observing effects on sweetness perception, as a reduction in fat levels may result in a reduction of perceived sweetness (Wiet et al, 1993;Biguzzi et al, 2014). Future studies should consider using for example a factorial design with interleaved trials to manipulate sugar and fat content (Smith et al, 2020).…”

Phase-locking of resting-state brain networks with the gastric basal electrical rhythm

“…In the present study, we acquired fMRI data only in the "resting" state. Researchers have used fMRI to measure brain responses to hedonic/gustatory stimuli such as photographs of food [57] and the the ingestion of small samples ("sips") of fluid delivered during scanning [58,59]. Concurrent EGG would allow future studies in this area to benefit from measures of how such stimuli affect the stomach's rhythm, and stomachbrain synchronization.…”