Acute exercise and appetite-regulating hormones in overweight and obese individuals: A meta-analysis

In lean individuals, acute aerobic exercise is reported to transiently suppress sensations of appetite, suppress blood-concentrations of acylated ghrelin (AG) and increase glucagon-like peptide-1 (GLP-1) and peptide-YY (PYY). Findings in overweight/obese individuals have yet to be synthesised.
In this systematic review and meta-analysis, we quantified the effects acute exercise has on AG, total PYY and GLP-1 in overweight/obese individuals. The potential for body mass index (BMI) to act as a moderator for AG was also explored.
Six published studies (73 participants, 78% male, mean BMI: 30.6 kg.m-2) met the inclusion criteria. Standardised mean differences (SMD) and standard errors were extracted for AG, total PYY and GLP-1 concentrations in control and exercise trials and synthesised using a random effects meta-analysis model. BMI was the predictor in a meta-regression for AG.
Exercise moderately suppressed AG area-under-the-curve concentrations (pooled SMD -0.34, 95%CI: -0.53 to -0.15). The magnitude of this reduction was greater for higher mean BMIs (pooled meta-regression slope: -0.04 SMD/kg.m-2 (95%CI: -0.07 to 0.00)). Trivial SMDs were obtained for total PYY (0.10, 95%CI: -0.13 to 0.31) and GLP-1 (-0.03, 95%CI: -0.18 to 0.13).
This indicates that exercise in overweight/obese individuals moderately alters AG in a direction that could be associated with decreased hunger and energy intake. (PROSPERO registration: CRD42014006265).