The Effect of Weekly Semaglutide Treatment on Energy Expenditure

Obesity is a complex chronic recurrent multifactorial disease characterized by abnormal or excessive body fat, which impairs physical health. In recent years, the glucagon like peptide-1 (GLP-1) receptor agonist semaglutide has attracted much attention due to its significant impact on weight loss. It can not only effectively control blood sugar by regulating the secretion of insulin and glucagon. It can also participate in certain brain regions of the body at pharmacological doses, regulating food intake and consumption. Semaglutide reduces energy intake and achieves weight loss by delaying gastric emptying, suppressing appetite, reducing hunger, and increasing satiety. This effect has been proven to be produced by activating the glucagon like peptide-1 (GLP-1) receptors in the central nervous system, further indirectly regulating the activity of neurons involved in appetite regulation, food intake, and preference. The previous results of using GLP-1 receptor agonist (RA) in rats and humans provide promising evidence data to support current randomized clinical trials. Peripheral administration of GLP-1 or GLP-1 RA can reduce blood sugar and energy intake in humans and rodents, and long-term treatment can lead to weight loss. In mice the drug also sustains energy expenditure at levels similar to controls, preventing the reduction that normally accompanies caloric restriction. Whether the same effects occur in humans is unclear because no studies have yet been performed comparing semaglutide treated individuals with those on a standard calorie restricted diet (in effect pair feeding). Therefore, in this study, researchers will use doubly- labelled water (DLW) and respiratory chambers to investigate whether semaglutide can prevent the reduction of energy expenditure that typically occurs during energy restriction.