The effect of glucagon-like peptide 1 and glucagon-like peptide 1 receptor agonists on energy expenditure: A systematic review and meta-analysis

We reviewed clinical trials addressing the effect of glucacon-like peptide 1 (GLP-1) or GLP-1 receptor agonists (GLP-1RA) on energy expenditure (EE) in adults. PubMed, Science Direct and Web of Science were searched for clinical trials investigating the effect of GLP-1 or GLP-1RA on EE in adults. Ten trials (93 participants) assessed the effect of GLP-1 administration over 1 to 48 h and found no change in resting EE (REE). Two out of three trials (62 participants) reported a significant decrease in diet-induced thermogenesis (DIT) following GLP-1 administration. Ten trials with exenatide (10 μg bid, for 10–52 weeks) or liraglutide (0.6, 1.2, 1.8 or 3 mg, for 3 days-52 weeks), with a total of 282 participants, indicated a neutral effect of these GLP-1RA on REE, DIT or physical activity-induced EE. Importantly, the longest trial with GLP-1RA reported a significant increase in REE in response to treatment with both exenatide or liraglutide and most trials reported that GLP-1RA-induced weight loss was not accompanied by decreased REE. This review indicates that GLP-1 has no short-term effect on REE but may decrease DIT. The GLP-1RA exenatide and liraglutide have a neutral effect on REE, although it is not possible to rule out an increase in REE following prolonged treatment.