Self-identified strategies to manage intake of tempting foods: cross-sectional and prospective associations with BMI and snack intake.

OBJECTIVES: Individuals often use self-directed strategies to manage intake of tempting foods, but what these strategies are and whether they are effective is not well understood. This study assessed the frequency of use and subjective effectiveness of self-directed strategies in relation to BMI and snack intake. DESIGN: A cross-sectional and prospective study with three time points (T1: baseline, T2: 3 months and T3: 3 years). At T1, demographics, frequency of use and subjective effectiveness of forty-one identified strategies were assessed. At T2 and T3, current weight was reported, and at T2 frequency of snack intake was also recorded. SETTING: Online study in the UK. PARTICIPANTS: Data from 368 participants (Mage = 34·41 years; MBMI = 25·06 kg/m2) were used for analysis at T1, n = 170 (46·20 % of the total sample) at T2 and n = 51 (13·59 %) at T3. RESULTS: Two strategy factors were identified via principal axis factoring: (1) diet, exercise, reduction of temptations, and cognitive strategies, and (2) planning, preparation and eating style. For strategy 1, frequency of use, but not subjective effectiveness, was positively related to BMI at T1. Subjective effectiveness predicted an increase in BMI from T1 and T2 to T3. No relationship to snack intake was found. For strategy 2, frequency of use was negatively related to BMI at T1. Neither frequency of use nor subjective effectiveness were related to changes in BMI over time, but subjective effectiveness was negatively correlated with unhealthy snack intake. CONCLUSION: Self-directed strategies to reduce the intake of tempting foods are not consistently related to BMI or snack intake.

Associations between dietary variety, portion size and body weight: prospective evidence from UK Biobank participants.

'Dietary variety' has been identified as a factor associated with food intake. Whilst this relationship may have longer-term benefits for body weight management when eating low-energy, nutrient-dense foods, it may increase the risk of overconsumption (and body adiposity) when foods are high energy density. This study sought to further explore pathways underpinning the relationship between dietary variety and body weight, by considering energy density as a moderating factor and portion size as a mediating factor in this relationship. Using prospective data from the UK Biobank, dietary variety scores (DVS), cumulative portion size and energy density were derived from 24-h dietary recall questionnaires at baseline and follow-up. BMI, whole-body fat percentage and fat-free mass were included as outcomes. Contrary to predictions, linear multiple regression models found some evidence of a negative, direct association between DVS and body weight outcomes at baseline (b = -0·13). Though dietary variety was significantly associated with larger portions across time points (b = 41·86-82·64), a moderated mediation effect was not supported at baseline or follow-up (Index ≤ 0·035). Taken together, these findings provide population-level evidence to support a positive association between variety and food intake, which in turn has potential implications for body weight management, both in terms of moderating food intake and benefitting diet quality.

Insular cortex activity during food-specific inhibitory control is associated with academic achievement in children.

BACKGROUND/OBJECTIVES: Inhibitory control (IC) is usually poorer in children with overweight and obesity and has been associated with unhealthy eating behaviors and lower academic achievement. Food-specific IC tasks depicting salient unhealthy foods may be more sensitive to predicting fat accumulation and unhealthy behaviors than traditional IC tasks. However, the neural activation patterns in response to food-specific IC remain unclear, especially in developing children`s brains. Here, we investigated brain activity associated with food-specific IC in children with accumulated fat mass. SUBJECTS/METHODS: 36 children with overweight and obesity performed a food-specific Go/No-Go task in an MRI scanner. We assessed the children's body composition with dual-energy x-ray absorptiometry, academic achievement, somatic maturation, and cardiorespiratory fitness. RESULTS: The left insular cortex was significantly activated during successful inhibition of palatable food cues and was associated with higher academic achievement. Also, linear regression showed that academic achievement correlated with insular cortex activation even when controlling for somatic maturation, cognitive performance, and cardiorespiratory fitness. CONCLUSION: Our results indicate that insular cortex activation, an area known for rational and emotional processing, is associated with successful inhibitory control in response to food images in children with overweight and obesity, while academic performance seems to play a role in the magnitude of this activation.

Identifying weight management clusters and examining differences in eating behaviour and psychological traits: An exploratory study.

Previous research has suggested differences in psychological traits and eating behaviours between groups of individuals with varying weight management profiles, for example, differences between individuals who have maintained weight loss compared to those who have not. However, no study has looked at differences in traits across a sample with a broad range of characteristics including variations in bodyweight and its management. Across two studies, we identified and validated weight management profiles using a clustering approach and examined trait differences across groups. Data were collected using online questionnaires (Study 1: secondary data analysis; Study 2: primary data analysis allowing for cluster validation). Cluster analysis was implemented with BMI, diet history, weight suppression (difference between highest and current weight) as primary grouping variables, and age and gender as covariates. Differences in psychological and eating behaviour traits (e.g., restraint) were explored across clusters. In study 1, 423 participants (27.21 ± 9.90 years) were grouped into 5 clusters: 'lean men', 'lean young women', 'lean middle-aged women', 'successful' and 'unsuccessful dieters'. The cluster structure was broadly replicated with two additional groups identified ('lean women without dieting' and 'very successful dieters') in study 2 with 368 participants (34.41 ± 13.63 years). In both studies, unsuccessful dieters had higher restrained and emotional eating scores than lean individuals, and in study 1, they also had higher food addiction scores than successful dieters. Individuals could be grouped in terms of their weight management profiles and differences in psychological and eating behaviour traits were evident across these groups. Considering the differences in traits between the clusters may further improve the effectiveness and adherence of weight management advice.

Testing an online measure of portion size selection: a pilot study concerned with the measurement of ideal portion size.

BACKGROUND: Portion size is known to be a key driver of food intake. As consumed portions are often pre-planned, 'ideal portion size'-an individual's preferred meal size selected prior to eating-has been identified as a strong predictor of actual consumption. However, assessments of ideal portion size have predominantly relied on laboratory-based computer tasks, limiting use online. Therefore, this cross-sectional study sought to pilot test the validity of a web-based tool to measure ideal portion size. METHODS: In an online study (N = 48), participants responded to images of a range of foods. Each food was photographed in a series of different portions and loaded into an 'image carousel' that would allow participants to change the size of the displayed portion by moving a slider left-to-right. Using this image carousel, participants selected their ideal portion size. They also completed measures of expected satiety and expected satiation and self-reported their age and body mass index (BMI). A non-parametric correlation matrix was used to explore associations between ideal portion size and identified predictors of food intake. RESULTS: Supporting convergent validity of this measure, ideal portion size was significantly correlated with expected satiety (rs = .480) and expected satiation (rs = -.310) after controlling for effects of baseline hunger and fullness, consistent with past research. Similarly, supporting divergent validity of this measure, ideal portion size was not significantly correlated with age (rs = -.032) or BMI (rs = -.111,). CONCLUSIONS: Pilot results support the validity of this web-based portion size selection tool used to measure ideal portion size, though further research is needed to validate use with comparisons to actual food intake.

Manipulating the sensation of feeling fat: The role of alexithymia, interoceptive sensibility and perfectionism.

OBJECTIVE: Feeling fat reflects difficulties in processing emotions and is an important aspect of body image and eating disorders. The current study aimed to develop a novel social comparison manipulation to induce feeling fat and to explore personality traits that may increase an individual's vulnerability. METHODS: At time 1, 254 healthy females (24.14 years, BMI = 23.77) completed the feeling fat subscale of the Body Attitudes Questionnaire, as well as self-report measures of alexithymia, interoceptive sensibility, physical appearance comparison and perfectionism online. At time 2, a subset of 107 participants (22.39 years, BMI = 23.85) were randomly assigned to a condition: negative social comparison, positive social comparison, negative general, or neutral (as a control). RESULTS: At time 1, greater tendency to feel fat was significantly associated with difficulty identifying and describing feelings (alexithymia), poorer interoceptive sensibility, higher socially-prescribed perfectionism, and greater engagement in physical appearance comparisons. At time 2, participants in the negative social comparison condition reported significantly greater increases in feeling fat compared to the control condition, but only when they were also high in alexithymia or socially-prescribed perfectionism. DISCUSSION: Current findings provide new insights into the potential mechanisms underpinning feeling fat and highlight how a novel social comparison manipulation can be used to induce the sensation of feeling fat.

Effect of food variety on intake of a meal: a systematic review and meta-analysis.

BACKGROUND: Many studies have shown that food variety-the presence of multiple foods and/or sensory characteristics within and across meals-increases intake. However, studies report mixed findings, and effect size remains unclear. OBJECTIVES: A systematic review and meta-analysis were conducted to 1) synthesize data across experimental studies that examined effects of variety on total meal intake, relative to a control condition with comparatively less variety; 2) quantify support for this effect; and 3) assist in the identification of important moderating factors (registration: CRD42019153585). METHODS: In November 2019, we searched the following databases for relevant experimental studies, published in English from 1980, with human participants: PubMed, Cochrane Library, Web of Science, ClinicalTrials.gov, PsycINFO, and OpenGrey. This search was updated in September 2020. Means, standard deviations, and sample sizes were extracted from included articles, and Hedges' g was used to calculate effect sizes. Risk of bias was assessed using the Cochrane Collaboration's tool. RESULTS: Of 7259 references identified in an initial search, 34 articles consisting of 37 studies contained sufficient information for review, and data from 30 studies (39 comparisons) were included in the meta-analysis. Results from a random-effects model showed a significant small to medium effect of variety on intake (in weight and energy), with greater variety being associated with increased consumption (Hedges' g = 0.405; 95% CI: 0.259, 0.552). However, heterogeneity was considerable across studies (I2 = 84%), and this was unexplained by subgroup analyses based on form of variety, test foods, sensory characteristics, age, sex, and body weight. CONCLUSIONS: Our findings support the conclusion that variety is a robust driver of food intake. However, risk of bias was high across studies, and this review highlights methodologic limitations of studies. It is recommended that further attention is given to the development of preregistered, well-powered randomized controlled studies in eating behavior research.

Susceptibility to increased high energy dense sweet and savoury food intake in response to the COVID-19 lockdown: The role of craving control and acceptance coping strategies.

Emerging evidence indicates that for some people, the COVID-19 lockdowns are a time of high risk for increased food intake. A clearer understanding of which individuals are most at risk of over-eating during the lockdown period is needed to inform interventions that promote healthy diets and prevent weight gain during lockdowns. An online survey collected during the COVID-19 lockdown (total n = 875; analysed n = 588; 33.4 ± 12.6 years; 82% UK-based; mostly white, educated, and not home schooling) investigated reported changes to the amount consumed and changes to intake of high energy dense (HED) sweet and savoury foods. The study also assessed which eating behaviour traits predicted a reported increase of HED sweet and savoury foods and tested whether coping responses moderated this relationship. Results showed that 48% of participants reported increased food intake in response to the COVID-19 lockdown. There was large individual variability in reported changes and lower craving control was the strongest predictor of increased HED sweet and savoury food intake. Low cognitive restraint also predicted greater increases in HED sweet snacks and HED savoury meal foods. Food responsiveness, enjoyment of food, emotional undereating, emotional overeating and satiety responsiveness were not significant predictors of changes to HED sweet and savoury food intake. High scores on acceptance coping responses attenuated the conditional effects of craving control on HED sweet snack intake. Consistent with previous findings, the current research suggests that low craving control is a risk factor for increased snack food intake during lockdown and may therefore represent a target for intervention.

Systolic blood pressure mediates the association between body mass index and inhibitory control in children.

Here, we examine whether systolic blood pressure (SBP) mediates the relationship between body mass index (BMI) and inhibitory control in children. Twenty children with high blood pressure (HBP) were approximately matched with twenty children with low blood pressure (LBP) by fitness, BMI, somatic maturation, sex and age. Inhibitory control was measured by a cognitive Go/Nogo task, where number of commission errors during Nogo trials and reaction time during Go trials were used as performance. We compared performance between the two groups and conducted a mediation analysis using SBP as mediator of the relationship between BMI and commission errors. Results revealed that HBP children presented higher number of commission errors, compared to LBP children. Moreover, SBP mediated the relation between BMI and number of errors. Thus, early exposure to high levels of SBP can negatively impact inhibitory control and SBP acts as a mediator between BMI and inhibitory functioning in children.

Consumer perception of food variety in the UK: an exploratory mixed-methods analysis.

BACKGROUND: 'Food variety' is a key term that is frequently used in dietary guidelines around the world. Consuming a variety of foods - be it within a meal, across meals, or as part of the whole diet - is one factor that has been shown to increase food intake. However, little is known about consumer understanding of variety, and this may be a potential barrier to the success of dietary guidelines in today's 'obesogenic' environment. This research sought to explore 1) consumer recognition of different forms of variety, and 2) consumer definitions of variety. METHODS: In an online study (N = 240), participants were asked to discuss a range of photographs depicting different forms of variety, and to directly define the term 'food variety'. They were unaware of the research aim. RESULTS: Using a mixed methods approach, directed content analysis of these data showed that individuals referenced multiple forms of variety in the presence of food photographs. However, when asked to define variety, participants tended to only discuss variety in the context of the whole diet. CONCLUSIONS: These findings emphasise a need to educate consumers about variety to encourage adherence to dietary guidelines and help consumers better manage their own food intake.

Impulsivity influences food intake in women with generalized anxiety disorder

Objective: Eating behavior is affected by psychological and neurocognitive factors. However, little is known about this relationship in anxious patients. Our aim was to investigate the associations between impulsivity, inhibitory control, energy-dense food consumption, and body mass index (BMI) in women with generalized anxiety disorder (GAD). Methods: In this cross-sectional study, 51 adult females with GAD answered the Barratt Impulsiveness Scale (BIS-11) and participated in a go/no-go task using food images. Anthropometric measurements were evaluated. A food frequency questionnaire and a snack test were used to study eating behavior. Pearson correlation and multiple linear regression were performed to analyze the variables of interest, adjusted by age. Results: Impulsivity predicted intake of sugar (p = 0.016, 95%CI 0.67-6.05), total fat (p = 0.007, 95%CI 0.62-3.71), and saturated fat (p = 0.004, 95%CI 0.30-1.48). The snack test showed a positive correlation between presence of impulsivity and intake of biscuits (R = 0.296; p = 0.051). Response inhibition to food images in the go/no-go task paradigm did not predict BMI or food intake. Conclusion: Impulsivity was predictive of higher sugar and saturated fat intake in women diagnosed with GAD. Our findings add to the literature regarding the association between neuropsychological factors and food consumption in this specific population.

Construal beliefs moderate the usability and effectiveness of a novel healthy eating mobile app.

Reduced self-control is a strong predictor of overeating and obesity. Priming a high construal level mind-set has been shown to enhance self-control and reduce snack consumption in the lab but the long-term and real-world effects are not known. The use of digital technology is an efficient way to deliver priming cues in real-world settings. Many mobile apps claim to support healthy eating but few are grounded in psychological theories of self-control. The aim of this study was to test the feasibility and effectiveness of a novel, construal-theory-based mobile app to promote self-control and healthy eating. In an exploratory analysis, the moderating influence of user characteristics was also examined. Using an iterative process involving users at every stage of the process, a prototype mobile app was developed. The final version included a high construal, self-control priming task, sent personalised reminder cues before each eating occasion, provided a just-in time 'crave-buster' for unanticipated eating opportunities and an optional food log. In a longitudinal trial the app was used over an eight-week period (N=71; 51 females; M (SD) Age = 33.34 (11.68) years; M (SD) BMI = 26.22 (4.94)) with pre-post measures of weight, percent body fat and dietary intake. The app received high usability ratings on the System Usability Scale (M=76.55; SD=11.35), however food intake, per cent body fat and weight pre- and post- app use showed no significant change (p>.05). Exploratory analyses showed that baseline construal belief moderated the extent to which engagement with the app predicted dietary changes (p<.05). These findings indicate that this novel app was user-friendly and effective but that this was dependent on the user's characteristics. Future development in this area should consider tailoring apps to the specific characteristics of the user for improved support and effectiveness.

Impulsivity influences food intake in women with generalized anxiety disorder.

OBJECTIVE: Eating behavior is affected by psychological and neurocognitive factors. However, little is known about this relationship in anxious patients. Our aim was to investigate the associations between impulsivity, inhibitory control, energy-dense food consumption, and body mass index (BMI) in women with generalized anxiety disorder (GAD). METHODS: In this cross-sectional study, 51 adult females with GAD answered the Barratt Impulsiveness Scale (BIS-11) and participated in a go/no-go task using food images. Anthropometric measurements were evaluated. A food frequency questionnaire and a snack test were used to study eating behavior. Pearson correlation and multiple linear regression were performed to analyze the variables of interest, adjusted by age. RESULTS: Impulsivity predicted intake of sugar (p = 0.016, 95%CI 0.67-6.05), total fat (p = 0.007, 95%CI 0.62-3.71), and saturated fat (p = 0.004, 95%CI 0.30-1.48). The snack test showed a positive correlation between presence of impulsivity and intake of biscuits (R = 0.296; p = 0.051). Response inhibition to food images in the go/no-go task paradigm did not predict BMI or food intake. CONCLUSION: Impulsivity was predictive of higher sugar and saturated fat intake in women diagnosed with GAD. Our findings add to the literature regarding the association between neuropsychological factors and food consumption in this specific population.

Fat mass predicts food-specific inhibitory control in children.

BACKGROUND/OBJECTIVES: Impaired inhibitory control has been associated with obesity, high blood pressure and lack of physical fitness. These impairments are thought to be related to decreased cognitive control over excessive food consumption and may start in childhood. However, previous studies in children have examined inhibitory control deficits using general (non-food-specific) tasks and relied on body mass index, which does not distinguish the amount of fat mass. As fat mass, hypertension and physical fitness have been shown to play a role in cognition, the aim of this study was to investigate the relationship between these variables and food specific inhibitory control in children. SUBJECTS/METHODS: Children's (n = 48; Age 10.7 ±â€¯0.6 years) general characteristics, fat mass, cardiorespiratory fitness, blood pressure and performance on a food-specific inhibitory control task (Go/No-go) were measured across two sessions. RESULTS: Fat mass and sex were associated with inhibitory control performance, while no associations were found for cardiorespiratory fitness, blood pressure and other potential confounding variables (i.e. age, pubertal timing, body mass index, waist-to-hip ratio, scholar test performance and heart rate). Linear regression analyses showed that only fat mass predicted poorer food-specific inhibitory control (ß = 0.36; ΔR2 = 0.04; p < .05) and sex predicted inhibitory control for toys (control condition) (ß = 0.42; ΔR2 = 0.11; p < .01). Neither blood pressure nor cardiorespiratory fitness predicted food specific inhibitory control. CONCLUSION: These findings suggest that fat mass is an independent predictor of inhibitory control for food in children.

Understanding everyday strategies used to manage indulgent food consumption: A mixed-methods design.

To maintain a healthy body weight or support weight loss efforts, dietary self-management must allow for the limitation of tempting high energy-dense foods. We were interested in people's implementation of day-to-day strategies in order to successfully manage their indulgent food and beverage consumption. Participants from the Swansea area, UK (N = 25; Mage = 37; 68% male) were divided into four focus groups. The average BMI was within the healthy range (23 kg/m2). Each group discussed the approaches that they used to manage their consumption of indulgent foods and drinks. Group discussions were then transcribed, thematically analysed and independently reviewed by a second researcher. In a follow-up phase, participants were asked to rate how often they used the identified strategies and to rate the perceived effectiveness of any that applied to them. The thematic analysis revealed four major themes: Exercise, Cognitive Strategies, Availability and Meal Formation. Variability in the frequency with which strategies were used and perceived as effective was evident. Notably, participants tended to use multiple strategies and even lean participants who did not identify themselves as 'dieters' none-the-less employed a variety of strategies to successfully manage their exposure to and consumption of tempting foods. The findings suggest that dietary advice could be improved by taking into account the strategies for managing indulgent food consumption that are frequently used by individuals, as well as those that are perceived as effective.

A serial mediation model of the relationship between alexithymia and BMI: The role of negative affect, negative urgency and emotional eating.

Difficulty identifying and describing emotions (alexithymia) has been related to impulsiveness and negative affect, emotional eating and obesity. However, previous research findings concerning the relationship between alexithymia and obesity have been mixed and inconsistent, raising the possibility that the relationship is indirect and mediated by multiple unknown factors. The aim of the study was to comprehensively explore the potential pathways between alexithymia and obesity via a novel theoretical model, and for the first time, incorporate negative affect, impulsiveness (negative urgency) and emotional eating as potential mediating factors. Two questionnaire-based studies were conducted; the first as an exploratory analysis within a student sample (N = 125), and the second as a self-replication within a more representative general population sample (N = 342). Study One revealed that difficulty identifying feelings predicted Body Mass Index (BMI) both directly (B = 0.1694, CI = 0.0194-0.3194) and indirectly via negative urgency and emotional eating (B = 0.0074, CI = 0.0001-0.0315). In contrast, Study Two revealed that alexithymia predicted BMI indirectly via negative affect (when depression was included in the model; B = 0.0335, CI = 0.0019-0.0660) or negative urgency (when anxiety was included in the model; B = 0.0021, CI = 0.0001-0.0066). Our findings provide partial support for the hypothesised model and offer original insight into the relationship between alexithymia and obesity. Additionally, our findings highlight important methodological considerations for future research and suggest that ways to address an individual's ability to identify, describe and regulate emotions should be considered when designing interventions to assist weight loss and management.

Self-control mediates the relationship between time perspective and BMI.

Trait future time perspective measures the extent to which behaviour is dominated by a striving for future goals and rewards. Trait present time perspective measures orientation towards immediate pleasure. Previous research has explored the relationship between future and present time perspective and BMI with mixed findings. In addition, the psychological mechanism underlying this relationship is unclear. Self-control is a likely candidate, as it has been related to both BMI and time perspective, but the relationship between all of these concepts has not been examined in a single study. Therefore, the aim of this study was to examine if trait self-control mediates the relationship between time perspective (future and present) and BMI. Self-report time perspective (ZTPI), self-control (SCS) and height/weight data were collected using an online survey from a mixed student and community sample (N = 218) with wide ranging age (mean 29, SD 11, range 18-73 years) and BMI (mean 24, SD 4, range 15-43). The results of a structural equation model including both facets of time perspective suggested that the traits are related yet distinct measures that independently predict BMI through changes in self-control. Bootstrap mediation analysis showed that self-control mediated the relationship between both future time perspective (95% CI, -0.10 to -0.02) and present time perspective (95% CI, 0.03 to 0.17), and BMI in opposite directions. Participants with higher future time perspective scores (higher present time perspective scores) had higher (lower) self-control, which predicted lower (higher) BMI. These results are consistent with previous research suggesting an important role for time perspective in health outcomes. Self-control likely mediates the relationship between temporal perspectives and BMI, suggesting that time perspective may be a target for individualised interventions.

Snack intake is reduced using an implicit, high-level construal cue.

OBJECTIVES: Priming a high level construal has been shown to enhance self-control and reduce preference for indulgent food. Subtle visual cues have been shown to enhance the effects of a priming procedure. The current study therefore examined the combined impact of construal level and a visual cue reminder on the consumption of energy-dense snacks. METHOD: A student and community-based adult sample with a wide age and body mass index (BMI) range (N = 176) were randomly assigned to a high or low construal condition in which a novel symbol was embedded. Afterward participants completed a taste test of ad libitum snack foods in the presence or absence of the symbol. RESULTS: The high (vs. the low) construal level prime successfully generated more abstract responses (p < .0001) and reduced intake when the cue-reminder was present (p = .02) but not when it was absent (p = .40). CONCLUSIONS: Priming high construal level thinking reduces consumption of high energy dense snacks in the presence of a visual cue-reminder. This may be a practical technique for reducing overeating and has the potential to be extended to other unhealthy behaviors. (PsycINFO Database Record

A dual-process approach to exploring the role of delay discounting in obesity.

Delay discounting of financial rewards has been related to overeating and obesity. Neuropsychological evidence supports a dual-system account of both discounting and overeating behaviour where the degree of impulsive decision making is determined by the relative strength of reward desire and executive control. A dual-parameter model of discounting behaviour is consistent with this theory. In this study, the fit of the commonly used one-parameter model was compared to a new dual-parameter model for the first time in a sample of adults with wide ranging BMI. Delay discounting data from 79 males and females (males=26) across a wide age (M=28.44years (SD=8.81)) and BMI range (M=25.42 (SD=5.16)) was analysed. A dual-parameter model (saturating-hyperbolic; Doya, [Doya (2008) ]) was applied to the data and compared on model fit indices to the single-parameter model. Discounting was significantly greater in the overweight/obese participants using both models, however, the two parameter model showed a superior fit to data (p<0.0001). The two parameters were shown to be related yet distinct measures consistent with a dual-system account of inter-temporal choice behaviour. The dual-parameter model showed superior fit to data and the two parameters were shown to be related yet distinct indices sensitive to differences between weight groups. Findings are discussed in terms of the impulsive reward and executive control systems that contribute to unhealthy food choice and within the context of obesity related research.