Priming food intake with weight control cues: systematic review with a meta-analysis

Abstract

BackgroundA growing number of studies suggest that exposure to cues which are associated with weight control can prime or prompt controlled food intake in tempting food environments. However, findings are mixed and understanding which types of cues and for whom such cues may be most effective is needed to inform subsequent research and societal applications. A systematic review and meta-analysis were conducted to evaluate the effects of exposure to weight control cues compared with control cues on food intake.MethodsPsycINFO, Medline, Embase and Web of Science were searched using key terms. Hedge’s g was used to calculate effect sizes based on mean food intake, standard deviations and sample sizes extracted from relevant publications and, a random effects model was used for the meta-analysis.ResultsTwenty-five articles consisting of 26 studies were eligible. Data from 25 studies (31 effect sizes) were available for the meta-analysis. Overall, weight control cues reduced food intake, albeit to a trivial effect (ES: -0.149, 95% CI: -0.271 to − 0.027). Subgroup analyses when studies which induced negative affect were removed showed that for individuals with strong weight control goals the effect was small-to-moderate (ES: -0.440, 95% CI: -0.718 to − 0.163), whereas for individuals with weak weight control goals this effect was trivial and non-significant (ES: 0.014, 95% CI: -0.249 to 0.278). Cue type and level of engagement did not significantly moderate the effect; however, specific cues (low-calorie foods and thin models) and attended engagement yielded significant effects. Caution is needed interpreting these findings as most studies were rated with high risk of bias and a number of studies could not be included in the subgroup analyses.ConclusionsBased on the data available, weight control cues reduce food intake in individuals with strong weight control goals. Further research is needed to explore longer term effects of cue exposure and confirm underlying mechanisms. PROSPERO registry#CRD42016052396.Electronic supplementary materialThe online version of this article (10.1186/s12966-018-0698-9) contains supplementary material, which is available to authorized users.

A Dieting Facilitator on the Fridge Door: Can Dieters Deliberately Apply Environmental Dieting Cues to Lose Weight?

“…Correspondingly, activated goals have been shown to have stronger effects on behavior when the positive affect related to the goals was higher—in other words, when goals were highly valued by the individuals holding the goals (see Bargh, 2016 ; see Papies, 2016b ; Weingarten et al, 2016 ). Also in line with this, environmental dieting cues have been shown to have a particularly pronounced effect on individuals who hold a chronic dieting goal, the restrained eaters ( Herman and Mack, 1975 ; Herman and Polivy, 1980 ; Weingarten et al, 2016 ; Polivy and Herman, 2017 ; see Buckland et al, 2018 ; Masterson et al, 2019 ). For example, only restrained eaters tasted fewer meat samples in a butcher shop when exposed to a poster on the entrance door that announced a weekly recipe as being low-calorie and “good for a slim figure” ( Papies and Hamstra, 2010 ).…”

“…These examples indicate that individuals were mostly exposed to dieting cues by others, without being aware that they were being influenced. In addition, mainly the short-term effects of environmental dieting cues were examined, such as the vending machine poster’s immediate effect on consumers’ snack choices ( Stöckli et al, 2016 ; see also Buckland et al, 2018 ). Yet, there remains a research gap regarding whether individuals can deliberately apply environmental dieting cues for themselves to facilitate the pursuit of their longer-term goal of losing weight.…”

“…Overall, dieting cues were found to reduce food intake only to a minor extent. In contrast, for individuals with a strong dieting goal, including both restrained eaters and dieters, a small-to-moderate effect was found ( Buckland et al, 2018 ). While restrained eaters are defined as having a chronic dieting goal or “concern for dieting” (see section “Measures”; Dinkel et al, 2005 ), dieters can be characterized as actively engaging in a weight management attempt at the moment and thus having a current dieting goal.…”

Implicit food odour priming effects on reactivity and inhibitory control towards foods

“…To study the modulation of behaviour by food cues, several studies focused on using priming [14,15]. Priming is how incidental stimuli (stimuli that are perceived without the individual's awareness or appreciation of their influence) are shown to influence higher-order cognitive and behavioural outcomes [16].…”

Image_1.pdf

“…In addition to the question of whether individuals can deliberately apply environmental cues for themselves to facilitate the pursuit of a personal goal, the present study addressed a second question that, to date, has received little attention: whether or not environmental cues in general (van Kleef and van Trijp, 2018) and dieting cues in particular can be applied effectively over a longer period of time (Papies, 2016b;Buckland et al, 2018). This is essential regarding the dieting goal, as losing weight requires time.…”