Factors Associated with Favorable Changes in Food Preferences After Bariatric Surgery.

PURPOSE: Bariatric surgery may shift food preferences towards less energy-dense foods. Eating behavior is multifactorial, and the mechanisms driving changes in food preferences could be a combination of a physiological response to surgery and social and psychological factors. This exploratory study aimed to identify potential factors explaining the variation in changes in food preferences after bariatric surgery. MATERIALS AND METHODS: Physiological, social, and psychological data were collected before, 6 weeks or 6 months after surgery. All variables were analyzed in combination using LASSO regression to explain the variation in changes in energy density at an ad libitum buffet meal 6 months after bariatric surgery (n=39). RESULTS: The following factors explained 69% of the variation in changes in food preferences after surgery and were associated with more favorable changes in food preferences (i.e., a larger decrease in energy density): female gender, increased secretion of glicentin, a larger decrease in the hedonic rating of sweet and fat and a fatty cocoa drink, a lower number of recent life crises, a low degree of social eating pressure, fulfilling the diagnostic criteria for binge eating disorder, less effort needed to obtain preoperative weight loss, a smaller household composition, a lower degree of self-efficacy and a higher degree of depression, nutritional regime competence, and psychosocial risk level. CONCLUSION: Factors explaining the variation in altered food preferences after bariatric surgery not only include a physiological response to surgery but also social and psychological factors.

Predictors of weight loss after bariatric surgery-a cross-disciplinary approach combining physiological, social, and psychological measures.

BACKGROUND: Bariatric surgery leads to a substantial weight loss (WL), however, a subset of patients undergoing surgery fails to achieve adequate WL. The reason for the individual variation in WL remains unexplained. Using an exploratory cross-disciplinary approach, we aimed to identify preoperative and early postoperative factors explaining the variation in WL after bariatric surgery. METHODS: Sixty-one subjects were recruited. Eighteen subjects did not receive surgery and three subjects dropped out, leaving a total sample of 40 subjects. Physiological, social, and psychological data were collected before and 6 months after surgery. All variables were analyzed in combination using a least absolute shrinkage and selection operator (LASSO) regression to explain the variation in WL 18 months after Roux-en-Y gastric bypass (n = 30) and sleeve gastrectomy (n = 10). RESULTS: Mean WL was 31% (range: 10-52%). The following preoperative factors predicted 59% of the variation in WL: type of surgery (14%), diabetes status (12%), economic resources (9%), sex (7%), binge eating disorder (7%), degree of depression (5%), household type (3%), and physical activity (1%). Including information on early responses after surgery increased the ability to predict WL to 78% and was explained by early WL (47%), changes in energy density of food consumed from a buffet meal (9%), changes in glicentin (5%), degree of depression (5%), sex (5%), type of surgery (2%), economic resources (2%), and changes in drive for thinness (1%). CONCLUSIONS: Using a cross-disciplinary approach, a substantial part of the individual variation in WL was explained by a combination of basic patient characteristics, psychological profile, and social conditions as well as physiological, psychological and behavioral responses to surgery. These results suggest that patient characteristics collected in a cross-disciplinary approach may help determine predictors for less successful WL after bariatric surgery. If verified in larger cohorts this may form the basis for individualized postoperative support to optimize WL outcome.

Patient profiling for success after weight loss surgery (GO Bypass study): An interdisciplinary study protocol.

Despite substantial research efforts, the mechanisms proposed to explain weight loss after gastric bypass (RYGB) and sleeve gastrectomy (SL) do not explain the large individual variation seen after these treatments. A complex set of factors are involved in the onset and development of obesity and these may also be relevant for the understanding of why success with treatments vary considerably between individuals. This calls for explanatory models that take into account not only biological determinants but also behavioral, affective and contextual factors. In this prospective study, we recruited 47 women and 8 men, aged 25-56 years old, with a BMI of 45.8 ±â€¯7.1 kg/m2 from the waiting list for RYGB and SL at Køge hospital, Denmark. Pre-surgery and 1.5, 6 and 18 months after surgery we assessed various endpoints spanning multiple domains. Endpoints were selected on basis of previous studies and include: physiological measures: anthropometrics, vital signs, biochemical measures and appetite hormones, genetics, gut microbiota, appetite sensation, food and taste preferences, neural sensitivity, sensory perception and movement behaviors; psychological measures: general psychiatric symptom-load, depression, eating disorders, ADHD, personality disorder, impulsivity, emotion regulation, attachment pattern, general self-efficacy, alexithymia, internalization of weight bias, addiction, quality of life and trauma; and sociological and anthropological measures: sociodemographic measures, eating behavior, weight control practices and psycho-social factors.Joining these many endpoints and methodologies from different scientific disciplines and creating a multi-dimensional predictive model has not previously been attempted. Data on the primary endpoint are expected to be published in 2018. TRIAL REGISTRATION: Clinicaltrials. gov ID NCT02070081.

Hedonic Changes in Food Choices Following Roux-en-Y Gastric Bypass.

It has been suggested that a shift in food choices leading to a diet with a lower energy density plays an important role in successful weight loss after Roux-en-Y gastric bypass (RYGB) surgery. A decreased hedonic drive to consume highly palatable foods may explain these changes in eating behavior. Here, we review the literature examining postoperative changes in mechanisms contributing to hedonic drive (food preferences, reinforcing value of food, dopamine signaling, and activity reward-related brain regions). The majority of studies reviewed support that RYGB decrease the hedonic drive to consume highly palatable foods. Still, in order to fully understand the complexity of these changes, we need studies combining sociological and psychological approaches with objective measures of actual food choices examining different measures of hedonic drive.

Effects of PYY3-36 and GLP-1 on energy intake, energy expenditure, and appetite in overweight men.

Our aim was to examine the effects of GLP-1 and PYY3-36, separately and in combination, on energy intake, energy expenditure, appetite sensations, glucose and fat metabolism, ghrelin, and vital signs in healthy overweight men. Twenty-five healthy male subjects participated in this randomized, double-blinded, placebo-controlled, four-arm crossover study (BMI 29 ± 3 kg/m(2), age 33 ± 9 yr). On separate days they received a 150-min intravenous infusion of 1) 0.8 pmol·kg(-1)·min(-1) PYY3-36, 2) 1.0 pmol·kg(-1)·min(-1) GLP-1, 3) GLP-1 + PYY3-36, or 4) placebo. Ad libitum energy intake was assessed during the final 30 min. Measurements of appetite sensations, energy expenditure and fat oxidation, vital signs, and blood variables were collected throughout the infusion period. No effect on energy intake was found after monoinfusions of PYY3-36 (-4.2 ± 4.8%, P = 0.8) or GLP-1 (-3.0 ± 4.5%, P = 0.9). However, the coinfusion reduced energy intake compared with placebo (-30.4 ± 6.5%, P < 0.0001) and more than the sum of the monoinfusions (P < 0.001), demonstrating a synergistic effect. Coinfusion slightly increased sensation of nausea (P < 0.05), but this effect could not explain the effect on energy intake. A decrease in plasma ghrelin was found after all treatments compared with placebo (all P < 0.05); however, infusions of GLP-1 + PYY3-36 resulted in an additional decrease compared with the monoinfusions (both P < 0.01). We conclude that coinfusion of GLP-1 and PYY3-36 exerted a synergistic effect on energy intake. The satiating effect of the meal was enhanced by GLP-1 and PYY3-36 in combination compared with placebo. Coinfusion was accompanied by slightly increased nausea and a decrease in plasma ghrelin, but neither of these factors could explain the reduction in energy intake.