Changes in eating behaviour and meal patterns following vertical sleeve gastrectomy

Abstract

Anecdotal evidence from clinical observations and evidence in rodents after vertical sleeve gastrectomy (VSG) suggest a shift in food preferences. Direct measures of behaviour to study the effects of VSG on the food preferences are unknown. This study aimed to investigate (1) Changes in eating behaviour and meal patterns after VSG, (2) Changes in sweet taste detection thresholds after VSG, (3) Changes in appetitive behaviour as a marker of changes in reward after VSG, and (4) Changes in consummatory behaviour as a marker of changes in reward after VSG in adolescents' subjects. The project recruited 50 adolescents after VSG and 35 as controls. The ages were 15 ± 0.27 and 14 ± 0.28 for the subjects after VSG and controls respectively. 42 % of the subjects were females and 58 % males, with the mean BMI of (51.1 ± 1.0) for VSG and (31.9 ± 1.1) for control subject. The parameters recorded for each aim included; Aim 1: Meal duration, meal size, pre-meal hunger and post-meal satiation that were assessed before and after VSG. Attitudes to foods, 24h recall method and FFQ were measured. Aim 2: The intensity of sweet taste stimuli assessed before and after VSG, using the constant stimuli methods. Aim 3: The appetitive reward of fat and sweet taste stimuli was assessed before and after VSG, using the Progressive Ratio Task. Aim 4: The consummatory reward of fat and sweet taste stimuli was assessed before and after VSG, using taste reactivity by recording and analysing facial expressions to determine the ingestive behaviour in response to stimulants. The results demonstrated; Aim 1: Changes in food preferences towards healthier choices, eating behaviour and meal pattern after VSG (all p <0.05). Aim 2: No changes in sucrose detection threshold after VSG (p= 0.6). Aim 3: Appetitive reward value as measured by the breakpoint of the tastant decreased after VSG (p=0.02). Aim 4: Consummatory reward value of the tastant as measured by behaviours associated with positive ingestive behaviours decreased after VSG as well (p= 0.03). In conclusion obese adolescents after VSG have a shift in food preferences to healthier food choices, as well as eating behaviour and meal patterns. VSG changed the Hedonic value of high fat and sugary food as suggested by changes in Appetitive and Consummatory behaviour in response. However VSG had no effect on the sensory domain as regards sweet sensitivity. Taken together VSG may improve the quality of food selected after surgery by reducing the reward value of high fat and sugary foods.