Eating attentively: a systematic review and meta-analysis of the effect of food intake memory and awareness on eating

Abstract

Background: Cognitive processes such as attention and memory may influence food intake, but the degree to which they do is unclear.

Objective: The objective was to examine whether such cognitive processes influence the amount of food eaten either immediately or in subsequent meals.

Design: We systematically reviewed studies that examined experimentally the effect that manipulating memory, distraction, awareness, or attention has on food intake. We combined studies by using inverse variance meta-analysis, calculating the standardized mean difference (SMD) in food intake between experimental and control groups and assessing heterogeneity with the I(2) statistic.

Results: Twenty-four studies were reviewed. Evidence indicated that eating when distracted produced a moderate increase in immediate intake (SMD: 0.39; 95% CI: 0.25, 0.53) but increased later intake to a greater extent (SMD: 0.76; 95% CI: 0.45, 1.07). The effect of distraction on immediate intake appeared to be independent of dietary restraint. Enhancing memory of food consumed reduced later intake (SMD: 0.40; 95% CI: 0.12, 0.68), but this effect may depend on the degree of the participants' tendencies toward disinhibited eating. Removing visual information about the amount of food eaten during a meal increased immediate intake (SMD: 0.48; 95% CI: 0.27, 0.68). Enhancing awareness of food being eaten may not affect immediate intake (SMD: 0.09; 95% CI: -0.42, 0.35).

Conclusions: Evidence indicates that attentive eating is likely to influence food intake, and incorporation of attentive-eating principles into interventions provides a novel approach to aid weight loss and maintenance without the need for conscious calorie counting.

Figures

FIGURE 1.

Literature search process guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PsycInfo (http://www.apa.org/pubs/databases/psycinfo/index.aspx), Medline (http://www.nlm.nih.gov/pubs/factsheets/medline.html), Embase (http://www.embase.com/), Web of Science (http://thomsonreuters.com/products_services/science/science_products/a-z/web_of_science/).

FIGURE 2.

Forest plot of comparisons between the experimental and control conditions for individual study types. BTV, participants watched a boring TV program; Exp, experiment; FoodTV, participants watched a TV program about food; FTV, participants watched a humorous TV program; IA, study included a condition examining increased attention on food intake; IV, inverse variance; Radio, experimental condition listened to a radio play; Reading, participants read a magazine article; Std., standardized; STV, participants watched a sad TV program; TV, participants watched TV.

FIGURE 3.

Forest plot of comparisons of the effect of distraction on immediate intake between the experimental and control conditions in participants with high or low restraint. Exp, experiment; FoodTV, participants watched a TV program about food; IV, inverse variance; Radio, experimental condition listened to a radio play; Std., standardized.

FIGURE 4.

Forest plot of comparisons of the effect of memory enhancement on later intake between the experimental and control conditions in participants with high or low disinhibition. Exp, experiment; IV, inverse variance; Std., standardized.