Investigating the Effects of Different Weight Loss Interventions on Eating Behaviour and Reward-Driven Eating in Patients with Obesity and Type 2 Diabetes

Abstract

Obesity has become a global health issue, and type-2 diabetes (T2DM) is one of its most common comorbidities. The Roux-en-Y gastric bypass (RYGB) is the most effective surgical procedure for treating obesity, resulting in significant and sustainable weight loss. One proposed mechanism for how RYGB achieves successful weight-loss is based on profound changes in the secretion of gastrointestinal hormones that follow surgery, including increases in Glucagon-Like Peptide-1, Oxyntomodulin and Peptide YY (GOP). Surgically induced changes in physiology are also associated with specific behavioural factors and psychological characteristics, both of which are recognised as important contributors to successful postoperative outcome. This study hypothesised that patients with obesity and T2DM following RYGB have a healthier eating behaviour profile, mediating the long-term sustainable weight loss than Very-Low-Calorie diet (VLCD) or GOP infusion. Eating behaviour, food reward, psychological status, health-related quality of life and food intake were assessed at baseline and following each intervention using a set of validated questionnaires and a 4-day food-diary before and after each intervention. The RYGB showed a reduction in the reward drive to eat at three-month which was maintained up to one-year post-surgery. There were also reductions in external-eating, disinhibition and weight and shape concerns which were not observed following VLCD or GOP, suggesting that calorie-restriction or gut-hormone alone maybe not be responsible for changes in eating behaviour following RYGB. Meanwhile, there were similarities between the RYGB and GOP groups in terms of the increase in the flexible dietary restraint measured by the Dutch Eating Behaviour questionnaire. Moreover, the GOP group did not show any changes in the taste perception as were observed following RYGB. Understanding the behavioural mechanisms that account for such variations could help the development of personalised therapeutic approaches based on the need to improve treatment outcomes and dietary advice offered to patients with obesity.