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.