Shift the paradigm to shift the weight: obesity care in the community

IntroductionObesity is a chronic relapsing condition characterised by abnormal or excessive accumulation of adipose tissue that presents a risk to health. It is associated with an increased risk of other chronic conditions including type 2 diabetes (T2DM), cardiovascular disease, renal and liver disease, musculoskeletal problems, and cancer. It can impact a person’s quality of life, wellbeing, and lifespan. Obesity is a complex condition, with a multitude of biological, social, environmental, and commercial factors, as well as food production and consumption processes, contributing to its development. One in four adults in the UK is living with obesity with comparable figures seen in children, and recent decades have seen an increase in prevalence

Effects of obesity surgery on food preferences, taste and reward in animals and humans

BACKGROUND: After Roux-en-Y gastric bypass bariatric surgery (RYGB) patients and animal models show a decreased preference for sweet/fatty foods. However, there are significant discrepancies in the findings of animal and human studies, and the mechanisms are not understood. AIMS: To investigate: 1. The effect of a high-fat (HFD) vs. low-fat (LFD) pre-operative maintenance diet on the ingestive behaviour of rats after RYGB 2. The effects of RYGB vs. gastric banding (BAND) surgery on food hedonics and brain reward systems in humans 3. The effects of RYGB on taste in humans METHODS: Study 1: Rats were fed either LFD or HFD before RYGB or sham surgery. Ingestive behaviour was assessed after surgery using food preference tests. Study 2: Brain reward responses to food were investigated using functional magnetic resonance imaging (fMRI), eating behaviour and metabolic phenotyping in body mass index (BMI) matched un-operated controls and patients after RYGB and BAND surgery. Study 3: The intensity and reward of sweet, fat and fat/sweet taste stimuli were assessed in patients undergoing RYGB using behavioural techniques. RESULTS: Study 1: Pre-operative maintenance diets with different fat contents, did not affect post-surgical weight loss or caloric intake. HFD-RYGB rats exhibited behaviour consistent with condition taste aversion to a familiar stimulus, compared to condition taste aversion to a novel stimulus in the LFD-RYGB rats. Study 2: Patients after RYGB had lower activation in brain reward systems to food and lower food hedonics than BAND patients and/or BMI-matched unoperated controls. Anorexigenic plasma gut hormones, plasma bile acids and dumping syndrome scores were higher in RYGB patients. Study 3: RYGB increased the intensity of fat/sweet taste solutions and reduced the reward value of fat/sweet stimuli. CONCLUSION: Pre-operative feeding may affect ingestive behaviour after RYGB. The mechanisms underlying the healthier food preferences after RYGB include the reduced reward value, and increased aversion to, high-calorie food and taste. Potential mediators are gut hormones, bile acids and altered gut nutrient sensing.Open Acces

Bariatric Surgery in Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine condition in premenopausal women and is a common cause of anovulatory subfertility. Although obesity does not form part of the diagnostic criteria, it affects a significant proportion of women with PCOS and is strongly implicated in the pathophysiology of the disease. Both PCOS and obesity are known to impact fertility in women; obesity also reduces the success of assisted reproductive technology (ART). With or without pharmacotherapy, lifestyle intervention remains the first-line treatment in women with PCOS and obesity. Bariatric surgery is still an experimental treatment in women with PCOS and subfertility. This review will present an overview of the pathophysiology of PCOS and obesity and the role of bariatric surgery. Although data are sparse regarding the impact of bariatric surgery on subfertility in women with PCOS and obesity, existing studies point to a beneficial role in treating metabolic and reproductive dysfunction. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.

Harnessing the Melanocortin System in the control of food intake and glucose homeostasis

The central and peripheral melanocortin system, comprising of five receptors and their endogenous ligands, is responsible for a wide array of physiological functions such as skin pigmentation, sexual function and development, and inflammation. A growing body of both clinical and pre-clinical research is demonstrating the relevance of this system in metabolic health. Disruption of hypothalamic melanocortin signalling is the most common cause of monogenic obesity in humans. Setmelanotide, an FDA-approved analogue of alpha-melanocyte stimulating hormone (α-MSH) that functions by restoring central melanocortin signalling, has proven to be a potent pharmacological tool in the treatment of syndromic obesity. As the first effective therapy targeting the melanocortin system to treat metabolic disorders, its approval has sparked research to further harness the links between these melanocortin receptors and metabolic processes. Here, we outline the structure of the central and peripheral melanocortin system, discuss its critical role in the regulation of food intake, and review promising targets that may hold potential to treat metabolic disorders in humans.</p

Mechanisms of weight loss after obesity surgery

Obesity surgery remains the most effective treatment for obesity and its complications. Weight loss was initially attributed to decreased energy absorption from the gut but have since been linked to reduced appetitive behaviour and potentially increased energy expenditure. Implicated mechanisms associating rearrangement of the gastrointestinal tract with these metabolic outcomes include central appetite control, release of gut peptides, change in microbiota and bile acids. However, the exact combination and timing of signals remain largely unknown. In this review, we survey recent research investigating these mechanisms, and seek to provide insights on unanswered questions over how weight loss is achieved following bariatric surgery which may eventually lead to safer, nonsurgical weight-loss interventions or combinations of medications with surger

Length of biliopancreatic limb in Roux-en-Y gastric bypass and its impact on post-operative outcomes in metabolic and obesity surgery-systematic review and meta-analysis

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is a gold-standard procedure for treatment of obesity and associated comorbidities. No consensus on the optimal design of this operation has been achieved, with various lengths of bypassed small bowel limb lengths being used by bariatric surgeons. This aim of this systematic review and meta-analysis was to determine whether biliopancreatic limb (BPL) length in RYGB affects postoperative outcomes including superior reduction in weight, body mass index (BMI), and resolution of metabolic comorbidities associated with obesity. METHODS: A systematic search of the literature was conducted up until 1st June 2021. Meta-analysis of primary outcomes was performed utilising a random-effects model. Statistical significance was determined by p value  0.05). Even though results of four studies showed superior total body weight loss in the long BPL cohorts at 24 months post-operatively (pooled mean difference −6.92, 95% CI –12.37, −1.48, p = 0.01), this outcome was not observed at any other timepoint. CONCLUSION: Based on the outcomes of the present study, there is no definitive evidence to suggest that alteration of the BPL affects the quantity of weight loss or resolution of co-existent metabolic comorbidities associated with obesity