Association between eating rate and obesity: a systematic review and meta-analysis

BACKGROUND: The association between eating rate and obesity has recently been reported. However, the findings remain inconclusive. OBJECTIVES: We undertook a systematic review with a meta-analysis of published epidemiological studies to provide a reliable close estimate of the association between eating rate and obesity. METHODS: A comprehensive search of MEDLINE, EMBASE and CINAHL was conducted to identify studies that reported quantitative estimates for indices of obesity based on the category of eating rate. Interventional studies or studies conducted using children as subjects were excluded. Two independent researchers extracted the data. A summary estimate was calculated using a random-effects model, and subgroup analyses were conducted to identify sources of heterogeneity. RESULTS: Data from 23 published studies were eligible for inclusion. The mean difference in body mass indices (BMIs) between individuals who ate quickly and those who ate slowly was 1.78 kg m(-2) (95% confidence interval (CI), 1.53-2.04 kg m(-2)). The pooled odds ratio of eating quickly on the presence of obesity was 2.15 (95% CI, 1.84-2.51). There was evidence of significant quantitative heterogeneity in the magnitudes of the association across studies (I-2 = 78.4%, P-value for heterogeneity < 0.001 for BMI, I-2 = 71.9%, P-value for heterogeneity < 0.001 for obesity), which may be partially explained by differences in the type of study population (a weaker association was observed for BMI in diabetic patients). CONCLUSIONS: Eating quickly is positively associated with excess body weight. Further studies are warranted to determine whether interventions to slow the speed of eating are effective for weight control.