Resistance reminders: Dieters reduce energy intake after exposure to diet-congruent food images compared to control non-food images

Anodal stimulation of inhibitory control and craving in satiated restrained eaters

OBJECTIVES

Eating and weight disorders are severe and complex clinical conditions which, among other behaviors, include (attempts at) restrained eating, food avoidance, following dietary rules, and overeating. Comparable to women with obesity, restrained eaters (RE) without formal eating disorder diagnosis are worse at inhibiting their motor responses than unrestrained eaters (URE). According to neuroimaging studies, the right inferior frontal gyrus (rIFG) is involved in inhibitory control which, in turn, could be improved by neuromodulation such as anodal transcranial direct current stimulation (tDCS) across rIFG.

METHODS

This double-blind sham-controlled cross-over study was conducted after a standardized breakfast. Normal-weight female RE und URE performed a stop-signal task (SST) with food and non-food stimuli during sham or anodal tDCS. Food craving, hunger, and satiety were self-reported before and after tDCS. We employed a mixed between-subjects (group: RE vs. URE) and within-subjects factorial design (tDCS: anodal tDCS vs. sham; stimuli: food vs. control pictures).

RESULTS

Breakfast consumption was comparable for RE and URE, as well as craving, hunger, and thirst. Regarding inhibitory control, a significant two-way interaction between group and tDCS ermerged: RE had longer stop-signal reaction times (SSRTs) during sham tDCS, but they improved to the level of URE by application of anodal tDCS.

DISCUSSION

Results replicated an inhibitory control deficit in RE with longer SSRTs compared to URE without stimulation. During anodal tDCS to the rIFG, reduced SSRTs in RE indicated an improvement in inhibitory control. The findings suggest a specificity of rIFG stimulation in at-risk groups with regards to inhibitory control irrespective of craving.

The impact of food packaging on measured food intake: A systematic review of experimental, field and naturalistic studies

Chronic, excess energy intake contributes to overweight and obesity. Solutions are needed to guide consumers towards portion control, especially for high energy density (HED), palatable foods. Food packaging, a key element of the eating environment, offers a potential solution. To investigate whether packaging design influences measured food intake, a systematic search was undertaken in four electronic databases (Ovid Medline; Ovid PsycInfo; Ovid Embase and Web of Science) across the previous decade. This process yielded 1671 discrete papers, of which 23 articles containing 40 relevant studies were retrieved. Most (n = 36) of the manipulated packaging features influenced consumption quantity with the largest effect sizes observed for packaging which guided consumers either by on-pack cues or structural features. For example, images on the front of the pack, packaging size, as well as partitioning and resealability all helped to reduce food intake. However, individual differences and attentional focus mediate packaging effects. Overall, packaging features can help to limit intake of HED foods and increase intake of nutrient-dense foods (e.g., carrots). Future studies on packaging for portion control (downsizing) might benefit from long term, randomised control trials to test effects outside of the laboratory context and applied to everyday consumer usage.

Restrained eaters' consumption of dietary forbidden and permitted foods after exposure to incidental fitness cues

The purpose of this research is to investigate the influence of incidental fitness cues on caloric food intake in restrained (vs. unrestrained) eaters. The authors show that the effect of incidental fitness cues (made salient via a priming procedure in a seemingly unrelated study prior to the main study) on caloric food intake differs between dietary forbidden and permitted foods. For food that is perceived as dietary forbidden, calorie intake decreases if restrained eaters are incidentally primed with fitness. In contrast, calorie intake of dietary permitted food increases for restrained eaters in response to incidental fitness primes. The study extends prior research on priming effects on eating behavior and derives important implications on how to help restrained eaters control energy intake.

The effect of the spatial positioning of a healthy food cue on food choice from a pictorial-style menu

The present study aimed to investigate the effect of the spatial positioning of a healthy food cue in the context of unhealthy food cues on subsequent food choice. Undergraduate women (N = 143) were asked to choose a food from a pictorial-style menu that presented a salad and three unhealthier food options in a horizontal line. The position of the salad was manipulated to be presented either (a) in the middle, (b) at the end, or (c) separated by 5 cm to the right of the line of unhealthier food options. Participants also completed a questionnaire measure of dietary restraint. Participants were significantly more likely to choose the salad when it was presented separately rather than in the middle of the unhealthier food options. This effect was not moderated by dietary restraint. The findings point to the possibility of designing pictorial menus in fast-food outlets in such a way as to subtly nudge people towards making healthier food choices.

Effects of Palatable Food Versus Thin Figure Conflicts on Responses of Young Dieting Women

Many young women use dieting to achieve a thinner figure yet most tend to fail as a result of heightened responsiveness to palatable food environments and increases in hedonic cravings. In this preliminary study, we developed a novel palatable food vs. thin figure conflict task to assess conflicting motives associated with eating among young women. Forty young dieting women [mean body mass index (BMI) = 22.98 kg/m², SD = 3.81] completed a food vs. figure conflict task within a 2 (distractor image: food vs. figure) × 2 (word-image congruence: congruent vs. incongruent) within-subjects design. Results supported the view that this new task could effectively capture conflict costs. Dieting young women displayed stronger food conflicts than figure conflicts based on having longer response delays and higher error rates in the food conflict condition than the figure conflict condition. Although young women often proclaimed "dieting" to achieve or maintain a good figure, dieters appeared to exhibit stronger preferences for palatable food cues relative to thin figure cues. These results provide important information for understanding automatic processing biases toward palatable foods and underscore the need for research extensions in other cultural contexts to determine whether such biases are universal in nature.

Do low-calorie sweetened beverages help to control food cravings? Two experimental studies

Low-calorie sweetened (LCS) beverages may help consumers to satisfy hedonic food cravings without violating dieting goals, however this remains unexplored. The present research investigated the effect of priming hedonic eating motivations on ad libitum energy intake in frequent and non-consumers of LCS beverages. It was hypothesised that energy intake would be greater after the hedonic eating prime relative to a control prime in non-consumers, but that frequent LCS beverage consumers would be protected from this effect. In Study 1 (N = 120), frequent and non-consumers were exposed to either chocolate or neutral cues (craving vs. control condition) and then completed a beverage-related visual probe task with concurrent eye-tracking. Ad libitum energy intake from sweet and savoury snacks and beverages (including LCS) was then assessed. Study 2 followed a similar protocol, but included only frequent consumers (N = 172) and manipulated the availability of LCS beverages in the ad libitum eating context (available vs. unavailable). Measures of guilt and perceived behavioural control were also included. In Study 1, as hypothesised, non-consumers showed greater energy intake in the craving condition relative to the control condition, but frequent consumers had similar energy intake in both conditions. Frequent consumers (but not non-consumers) also demonstrated an attentional bias for LCS beverage stimuli compared to both sugar and water stimuli. In contrast, in Study 2 frequent consumers showed greater energy intake in the craving condition relative to the control condition; however, overall energy intake was significantly greater when LCS beverages were unavailable compared to when they were available. Ratings of guilt were higher and perceived control was lower in the LCS-unavailable condition relative to the LCS-available condition. Conclusions: LCS beverages did not consistently protect consumers from craving-induced increases in energy intake. However, frequent consumers consumed fewer calories overall when LCS beverages were available (relative to unavailable), as well as perceiving more control over their food intake and feeling less guilty.

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

BACKGROUND

A 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.

METHODS

PsycINFO, 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.

RESULTS

Twenty-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.

CONCLUSIONS

Based 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.

Restrained Eating and Food Cues: Recent Findings and Conclusions

PURPOSE OF REVIEW

The purposes of the present review are to organize the recent literature on the effects of food cues on restrained and unrestrained eaters and to determine current directions in such work.

RECENT FINDINGS

Research over the last several years involves both replicating the work showing that restrained eaters respond to attractive food cues by eating more but unrestrained eaters show less responsiveness and extending this work to examine the mechanisms that might underlie this differential responsiveness. Labeling a food as healthy encourages more eating by restrained eaters, while diet-priming cues seem to curtail their consumption even in the face of attractive food cues. Work on cognitive responses indicates that restrained (but not unrestrained) eaters have both attention and memory biases toward food cues. Restrained eaters attend more strongly to food- and diet-related cues than do unrestrained eaters, as evidenced in both their eating behavior and their attention and memory responses to such cues. These effects interact with expectations and manner of presentation of such cues. What remains to be understood is the meaning and mechanism of the attention bias toward food cues in restrained eaters and the implications of such bias for overeating and overweight more broadly speaking.

Health goal priming as a situated intervention tool: how to benefit from nonconscious motivational routes to health behaviour

Recent research has shown the limited effects of intentions on behaviour, so that novel methods to facilitate behaviour change are needed that do not rely on conscious intentions. Here, it is argued that nonintentional effects on health behaviour, such as the effects of habits, impulses, and nonconscious goals, occur through the activation of cognitive structures by specific situations. Interventions should therefore be situated to change these effects, either by changing the critical cognitive structures (training interventions), or by changing which cognitive structures get activated (cueing interventions). The current article presents this framework for situated interventions, as well as examples of interventions of each type. Then, it introduces goal priming as a cueing intervention tool to activate health goals and thus facilitate healthier behaviour, even in tempting situations that typically activate short-term hedonic goals. Following a review of empirical evidence, five principles for the effective application of health goal primes are proposed, namely (1) to target individuals who value the primed goals, (2) by activating their specific motivation, (3) through effective cues (4) that attract attention at the right time. Finally, (5) an effective goal-directed behaviour needs to be known and accessible to the primed individual. These principles are illustrated with examples of different health behaviours in order to facilitate their application for successful behaviour change.