A systematic review and meta-analysis examining the effect of eating rate on energy intake and hunger

Background: Reductions in eating rate are recommended to prevent and treat obesity; yet, the relation between eating rate and energy intake has not been systematically reviewed, with studies producing mixed results. Objective: Our main objective was to examine how experimentally manipulated differences in eating rate influence concurrent energy intake and subjective hunger ratings. Design: We systematically reviewed studies that experimentally manipulated eating rate and measured concurrent food intake, self-reported hunger, or both. We combined effect estimates from studies by using inverse variance meta-analysis, calculating the standardized mean difference (SMD) in food intake between fast and slow eating rate conditions. Results: Twenty-two studies were eligible for inclusion. Evidence indicated that a slower eating rate was associated with lower energy intake in comparison to a faster eating rate (random-effects SMD: 0.45; 95% CI: 0.25, 0.65; P < 0.0001). Subgroup analysis indicated that the effect was consistent regardless of the type of manipulation used to alter eating rate, although there was a large amount of heterogeneity between studies. There was no significant relation between eating rate and hunger at the end of the meal or up to 3.5 h later. Conclusions: Evidence to date supports the notion that eating rate affects energy intake. Research is needed to identify effective interventions to reduce eating rate that can be adopted in everyday life to help limit excess consumption.