Aspects of Obesity: From aetiology to weight loss and maintenance

Abstract

Introduction Obesity is a significant global health and financial issue with prevalence increasing. While the cornerstone of its management remains a combined lifestyle intervention, weight loss recidivism is high. Recent novel insights relating to dietary protein and to weight homeostasis and neuro-endocrine adaptation shed light on these important aspects of obesity. Results Experiment 1 demonstrated that in lean health adults, after 4 days of ad libitum diets followed by a standardised breakfast, the lowest %protein diet was associated with highest fasting ghrelin and lowest post-prandial cholecystokinin. Experiment 2 demonstrated that both obese and lean mice varied daily food intake by >12% when consuming low protein compared to high protein chow. Experiment 3 demonstrated in obese adults that weight loss by combined lifestyle intervention was associated with reduced fasting ghrelin and glucagon-like peptide-1. Discussion The intake for dietary protein is prioritised even at the expense of increased total energy consumption and the physiological effects of changes to gut hormones on low protein diets is to favour hunger. The secular trend of reduced energy intake by protein may be a key driver towards obesity. Weight regain after lifestyle interventions are due to changes in mediators of appetite and body weight rather than just a failure of behaviour. These results challenge the conventional understanding about obesity.