Development of Momentary Appetite Capture (MAC): A versatile tool for monitoring appetite over long periods.

Understanding how an intervention impacts appetite in real-life settings and over several days remains a challenging and under-explored research question. To this end, we developed Momentary Appetite Capture (MAC), a form of ecological momentary assessment that combines automated text messaging with an online platform. Participants report their appetite using visual analogue scales (hunger, desire to eat, and fullness) and a virtual portion-size selection task. In two separate studies, we assessed the feasibility and test-retest reliability of MAC. Participants were prompted every 2 hours over a 14-hour window, and they repeated this assessment over two consecutive weekdays. For each participant, we calculated a daily time-averaged area under the curve (AUC) for each appetite measure. In Study One (N = 25) time-averaged AUC was significantly positively correlated across test days for hunger (r = 0.563, p = .003), desire to eat (r = 0.515, p = .008) and prospective portion size (r = 0.914, p < .001), but not for fullness (r = 0.342, p = .094). Participants completed 95% of MACs (380 of 400), and we used participant feedback to improve the MAC tool and study protocol for Study Two. In Study Two (N = 31), 94% of MACs were completed (468 of 496). Across days, time-averaged AUC was significantly positively correlated for hunger (r = 0.595, p = < .001), fullness (r = 0.501, p = .004), desire to eat (r = 0.585, p < .001), and prospective portion size (r = 0.757, p < .001). Together, these studies suggest that MAC could be an acceptable and reliable tool to track appetite throughout the day. In the future, MAC could be used to explore the impact of weight-loss interventions on natural fluctuations in appetite.

Meat disgust is negatively associated with meat intake - Evidence from a cross-sectional and longitudinal study.

Meat consumption is increasingly seen as unsustainable, unhealthy, and unethical. Understanding what factors help people reduce their meat intake is urgently needed. One such factor is meat disgust, a feeling reported by many vegetarians, and which could be a promising basis for meat reduction interventions. However, meat disgust and its impact on meat consumption is poorly understood. We examined meat disgust and its role in vegetarianism and reducing meat intake in a cross-sectional and longitudinal online study. We measured self-reported meat consumption, meat disgust (by self-report and Implicit Association Test), meat liking, self-control, and disgust sensitivity in N = 711 adults (57% omnivores, 28% flexitarians, 15% vegetarians) recruited from a community cohort. Results showed that 73% of vegetarians can be classified as 'meat disgusted', and that meat disgust predicted meat intake better than self-control in omnivores and flexitarians at baseline. Following up a sub-sample of participants (N = 197) after six months revealed that changes in meat intake over time were also associated with changes in meat disgust. This is the first study to quantify the impact of meat disgust on (changes in) meat consumption and its prevalence in the vegetarian and the general population. Our findings advance research into meat disgust and encourage the development of disgust-based interventions to reduce meat intake.

App-based food Go/No-Go training: User engagement and dietary intake in an opportunistic observational study.

Food Go/No-Go training aims to alter implicit food biases by creating associations between perceiving unhealthy foods and withholding a dominant response. Asking participants to repeatedly inhibit an impulse to approach unhealthy foods can decrease unhealthy food intake in laboratory settings. Less is known about how people engage with app-based Go/No-Go training in real-world settings and how this might relate to dietary outcomes. This pragmatic observational study investigated associations between the number of completed app-based food Go/No-Go training trials and changes in food intake (Food Frequency Questionnaire; FFQ) for different healthy and unhealthy food categories from baseline to one-month follow-up. In total, 1234 participants (m(BMI) = 29 kg/m2, m(age) = 43years, 69% female) downloaded the FoodT app and completed food-Go/No-Go training at their own discretion (mean number of completed sessions = 10.7, sd = 10.3, range: 1-122). In pre-registered analyses, random-intercept linear models predicting intake of different foods, and controlled for baseline consumption, BMI, age, sex, smoking, metabolic syndrome, and dieting status, revealed small, significant associations between the number of completed training trials and reductions in unhealthy food intake (b = -0.0005, CI95= [-0.0007;-0.0003]) and increases in healthy food intake (b = 0.0003, CI95 = [0.0000; 0.0006]). These relationships varied by food category, and exploratory analyses suggest that more temporally spaced training was associated with greater changes in dietary intake. Taken together, these results imply a positive association between the amount of training completed and beneficial changes in food intake. However, the results of this pragmatic study should be interpreted cautiously, as self-selection biases, motivation and other engagement-related factors that could underlie these associations were not accounted for. Experimental research is needed to rule out these possible confounds and establish causal dose-response relationships between patterns of engagement with food Go/No-Go training and changes in dietary intake.

When do children learn how to select a portion size?

The reduction of portion sizes supports weight-loss. This study looks at whether children have a conceptual understanding of portion size, by studying their ability to manually serve a portion size that corresponds to what they eat. In a clinical setting, discussion around portion size is subjective thus a computerised portion size tool is also trialled, with the portion sizes chosen on the screen being compared to amounts served manually. Children (n = 76) age 5-6, 7-8 and 10-11 were asked to rate their hunger (VAS scale), liking (VAS scale) and 'ideal portion size for lunch' of eight interactive meal images using a computerised portion size tool. Children then manually self-served and consumed a portion of pasta. Plates were weighed to allow for the calculation of calories served and eaten. A positive correlation was found between manually served food portions and the amount eaten (r = 0.53, 95%CI [0.34, 0.82, P < .001), indicating that many children were able to anticipate their likely food intake prior to meal onset. A regression model demonstrates that age contributes to 9.4% of the variance in portion size accuracy (t(68) = -2.3, p = .02). There was no relationship between portion size and either hunger or liking. The portion sizes chosen on the computer at lunchtime correlated to the amount manually served overall (r = .34, 95%CI [0.07, 0.55], p < .01), but not in 5-6-year-old children. Manual portion-size selection can be observed in five-year olds and from age seven, children's 'virtual' responses correlate with their manual portion selections. The application of the computerised portion-size tool requires further development but offers considerable potential.

Food-related inhibitory control training reduces food liking but not snacking frequency or weight in a large healthy adult sample.

Inhibitory control training has recently been used as an intervention to aid healthy eating and encourage weight loss. The aim of this pre-registered study was to explore the effects of training on food liking, food consumption and weight loss in a large (n = 366), predominantly healthy-weight sample. Participants received four training sessions within a week, in which they had to inhibit their responses to either energy-dense foods (active group) or non-food images (control group). Subjective food ratings, food consumption frequency and weight were measured pre- and post-training. At two-weeks post-training, the active group reported a greater reduction in liking for energy-dense foods, compared to the control group. Active participants also reported a significantly greater increase in healthy food liking, immediately post-training, relative to the control group. There was no statistically significant difference between groups for the change in consumption of trained foods or for weight loss. These findings are partially consistent with previous research conducted in smaller, more overweight samples. Exploratory analyses suggest that some effects of training may be driven by awareness effects. Methodological differences across findings and avenues for future investigation are discussed.

Giving pork the chop: Response inhibition training to reduce meat intake.

Meat consumption is damaging to the environment, health and animal welfare. Despite a growing interest in reducing meat intake, many people eat too much. This is partly due to the pleasure associated with eating meat. Research has used go/no-go response inhibition training (RIT) to reduce the intake and reward value (liking) of snack foods. However, RIT has not yet been applied to meat. We investigated whether an internet-delivered RIT with meat pictures would reduce meat intake and liking relative to a non-food control RIT condition. Participants (N = 81) were meat eaters with a desire to reduce their intake. They completed four 10-min training sessions in one week. Active participants inhibited responses to meat, and responded to fruits and vegetables. Meat intake was measured using food frequency questionnaires at pre- and one month post-training, and a daily meat diary for one week during training. Liking of meat and other foods was measured at pre- and one month post-training. There was a reduction in meat intake over one month in both groups, with active participants showing a significantly larger decrease than controls. Conditions did not differ in meat intake during the training week. Both groups showed a devaluation of meat, with active participants showing a significantly larger devaluation of food overall, suggesting some generalisation of devaluation effects. The reduced frequency of meat intake was associated with greater devaluation of meat in active but not control participants. These findings suggest that meat RIT helps to reduce meat intake and food liking. Future research should conduct larger randomised controlled trials with longer-term outcomes.

A randomised controlled trial examining the efficacy of smoking-related response inhibition training in smokers: a study protocol.

BACKGROUND: Smoking is one of the leading preventable causes of illness and premature death worldwide. Despite a variety of effective treatments, relapse rates remain high, and novel, innovative interventions are needed in order to reduce the global prevalence of smoking. Research has indicated that deficits in the ability to inhibit a response (referred to as response inhibition) is a predictor of relapse and subsequently, targeting this potentially modifiable risk factor may lead to improvements in smoking outcomes. Indeed, in recent years, stimulus-specific response inhibition training has emerged as a potentially efficacious intervention to reduce unwanted/unhealthy behaviours such as alcohol and unhealthy food consumption. As such, the present trial is the first to evaluate the real-world efficacy of response inhibition smoking training (INST) in a sample of adult heavy smokers. METHODS/DESIGN: This randomised controlled trial will recruit nicotine dependent smokers aged between 18 and 60 using social media and advertisements in Victoria, Australia. The sample target was 150 to account for drop out and non-adherence. Once informed consent has been obtained, participants complete a range of baseline measures during a face to face interview. Participants are randomly allocated to one of two online training conditions: an intervention training group (INST), which requires participants to exercise response inhibition towards smoking-related stimuli; or an active control group, which requires participants to exercise response inhibition towards household items and does not include any smoking-related stimuli. They complete the first training session during the interview to ensure the training protocol is clear. Both groups are instructed to complete a further 13 training sessions (1 per day) at home on their computer and follow-up phone calls will be conducted at three time points: post-intervention, one-month and three months. The primary outcomes are: a) rates of smoking cessation and; b) reduction in the quantity of average daily smoking at post-intervention, one and three months follow-up. DISCUSSION: There is a pressing need to develop novel and innovative smoking interventions. If proven to be effective, INST could make a highly cost-effective contribution to improvements in smoking intervention outcomes. TRIAL REGISTRATION: The trial was prospectively registered with the Australian New Zealand Clinical Trials Registry 17th February 2017. Trial ID: ACTRN12617000252314 .

To Go or Not to Go: A Proof of Concept Study Testing Food-Specific Inhibition Training for Women with Eating and Weight Disorders.

Inefficient food-specific inhibitory control is a potential mechanism that underlies binge eating in bulimia nervosa and binge eating disorder. Go/no-go training tools have been developed to increase inhibitory control over eating impulses. Using a within-subjects design, this study examined whether one session of food-specific go/no-go training, versus general inhibitory control training, modifies eating behaviour. The primary outcome measure was food consumption on a taste test following each training session. Women with bulimia nervosa and binge eating disorder had small non-significant reductions in high-calorie food consumption on the taste test following the food-specific compared with the general training. There were no effects on eating disorder symptomatic behaviour (i.e. binge eating/purging) in the 24 h post-training. The training task was found to be acceptable by the clinical groups. More research is needed with larger sample sizes to determine the effectiveness of this training approach for clinical populations. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Training response inhibition to reduce food consumption: Mechanisms, stimulus specificity and appropriate training protocols.

Training individuals to inhibit their responses towards unhealthy foods has been shown to reduce food intake relative to a control group. Here we aimed to further explore these effects by investigating the role of stimulus devaluation, training protocol, and choice of control group. Restrained eaters received either inhibition or control training using a modified version of either the stop-signal or go/no-go task. Following training we measured implicit attitudes towards food (Study 1) and food consumption (Studies 1 and 2). In Study 1 we used a modified stop-signal training task with increased demands on top-down control (using a tracking procedure and feedback to maintain competition between the stop and go processes). With this task, we found no evidence for an effect of training on implicit attitudes or food consumption, with Bayesian inferential analyses revealing substantial evidence for the null hypothesis. In Study 2 we removed the feedback in the stop-signal training to increase the rate of successful inhibition and revealed a significant effect of both stop-signal and go/no-go training on food intake (compared to double-response and go training, respectively) with a greater difference in consumption in the go/no-go task, compared with the stop-signal task. However, results from an additional passive control group suggest that training effects could be partly caused by increased consumption in the go control group whereas evidence for reduced consumption in the inhibition groups was inconclusive. Our findings therefore support evidence that inhibition training tasks with higher rates of inhibition accuracy are more effective, but prompt caution for interpreting the efficacy of laboratory-based inhibition training as an intervention for behaviour change.

Emotion regulation deficits in euthymic bipolar I versus bipolar II disorder: a functional and diffusion-tensor imaging study.

OBJECTIVES: Emotion regulation deficits are a core feature of bipolar disorder. However, their potential neurobiological underpinnings and existence beyond bipolar I disorder remain unexplored. Our main goal was to investigate whether both individuals with bipolar I and bipolar II disorder show deficits in emotion regulation during an attention control task, and to explore the neurophysiological underpinnings of this potential deficit. METHODS: Twenty healthy controls, 16 euthymic participants with bipolar I disorder, and 19 euthymic participants with bipolar II disorder completed psychometric and clinical assessments, a neuroimaging emotion regulation paradigm, and an anatomical diffusion-weighted scan. Groups were matched for age, gender, and verbal IQ. RESULTS: During the presence of emotional distracters, subjects with bipolar I disorder showed slowed reaction times to targets, and increased blood oxygenation level-dependent (BOLD) responses in the amygdala, accumbens, and dorsolateral prefrontal cortex, but not increased inverse functional connectivity between these prefrontal and subcortical areas, and altered white matter microstructure organization in the right uncinate fasciculus. Subjects with bipolar II disorder showed no altered reaction times, increased BOLD responses in the same brain areas, increased inverse functional connectivity between the prefrontal cortex and amygdala, and no abnormalities in white matter organization. CONCLUSIONS: Participants with bipolar I disorder showed abnormalities in functional and anatomical connectivity between prefrontal cortices and subcortical structures in emotion regulation circuitry. However, these deficits did not extend to subjects with bipolar II disorder, suggesting fundamental differences in the pathophysiology of bipolar disorder subtypes.

Stopping to food can reduce intake. Effects of stimulus-specificity and individual differences in dietary restraint.

Overeating in our food-rich environment is a key contributor to obesity. Computerised response-inhibition training could improve self-control in individuals who overeat. Evidence suggests that training people to inhibit motor responses to specific food pictures can reduce the subsequent choice and consumption of those foods. Here we undertook three experiments using the stop-signal task to examine the effects of food and non-food related stop-training on immediate snack food consumption. The experiments examined whether training effects were stimulus-specific, whether they were influenced by the comparator (control) group, and whether they were moderated by individual differences in dietary restraint. Experiment 1 revealed lower intake of one food following stop- vs. double- (two key-presses) response training to food pictures. Experiment 2 offered two foods, one of which was not associated with stopping, to enable within- and between-subjects comparisons of intake. A second control condition required participants to ignore signals and respond with one key-press to all pictures. There was no overall effect of training on intake in Experiment 2, but there was a marginally significant moderation by dietary restraint: Restrained eaters ate significantly less signal-food following stop- relative to double-response training. Experiment 3 revealed that stop- vs. double-response training to non-food pictures had no effect on food intake. Taken together with previous findings, these results suggest some stimulus-specific effects of stop-training on food intake that may be moderated by individual differences in dietary restraint.

Training response inhibition to food is associated with weight loss and reduced energy intake.

The majority of adults in the UK and US are overweight or obese due to multiple factors including excess energy intake. Training people to inhibit simple motor responses (key presses) to high-energy density food pictures reduces intake in laboratory studies. We examined whether online response inhibition training reduced real-world food consumption and weight in a community sample of adults who were predominantly overweight or obese (N = 83). Participants were allocated in a randomised, double-blind design to receive four 10-min sessions of either active or control go/no-go training in which either high-energy density snack foods (active) or non-food stimuli (control) were associated with no-go signals. Participants' weight, energy intake (calculated from 24-h food diaries), daily snacking frequency and subjective food evaluations were measured for one week pre- and post-intervention. Participants also provided self-reported weight and monthly snacking frequency at pre-intervention screening, and one month and six months after completing the study. Participants in the active relative to control condition showed significant weight loss, reductions in daily energy intake and a reduction in rated liking of high-energy density (no-go) foods from the pre-to post-intervention week. There were no changes in self-reported daily snacking frequency. At longer-term follow-up, the active group showed significant reductions in self-reported weight at six months, whilst both groups reported significantly less snacking at one- and six-months. Excellent rates of adherence (97%) and positive feedback about the training suggest that this intervention is acceptable and has the potential to improve public health by reducing energy intake and overweight.

Almost winning: induced MEG theta power in insula and orbitofrontal cortex increases during gambling near-misses and is associated with BOLD signal and gambling severity.

In slot machine gambling, the "near-miss effect" (when a losing display physically resembles an actual win display) has been implicated in pathological gambling (PG). Functional magnetic resonance imaging (fMRI) with PG and non-PG participants shows that near-misses recruit reward-related circuitry, but little is known about the temporal dynamics and oscillatory changes underlying near-misses. The present multi-modal imaging study investigated the near-miss effect by combining the spatial resolution of blood oxygen-level dependent (BOLD)-fMRI with the spatial and temporal resolution of magnetoencephalography (MEG) during a slot machine task in PG and non-PG groups. Given previous findings on outcome (win and near-miss) processing, functional overlap was hypothesized between induced changes in temporal oscillations and BOLD response to wins and near-misses in PG. We first validated our task in a sample of varying gambling severity using BOLD-fMRI and then compared PG and non-PG participants using MEG to investigate changes in induced oscillatory power associated with win and near-miss, relative to loss, outcomes. Across both modalities, near-misses recruited similar brain regions to wins, including right inferior frontal gyrus and insula. Using MEG, increased theta-band (4-7Hz) oscillations to near-misses were observed in the insula and right orbitofrontal cortex (OFC). Furthermore, this theta-band activity was positively associated with gambling severity. These findings demonstrate that the near-miss effect in insula and OFC is associated with induced theta oscillations. The significance of these findings for theories of PG and the development of potential biomarkers and therapeutic targets is discussed.

Decision-making deficits in pathological gambling: the role of executive functions, explicit knowledge and impulsivity in relation to decisions made under ambiguity and risk.

BACKGROUND: A variety of cognitive and emotional processes influence the decision-making deficits observed in pathological gambling (PG). This study investigated the role of immediate/delayed sensitivity to reward and punishment, executive functions, impulsivity and explicit knowledge in relation to decision-making performance on the original Iowa Gambling Task (IGT-ABCD) and a variant (IGT-EFGH). METHODS: We assessed 131 consecutive patients with a diagnosis of PG by using executive functioning and decision-making tasks, self-report measures of impulsivity and explicit knowledge. RESULTS: The majority of pathological gamblers (PGs) showed deficits in decision-making, characterized mainly by myopia for the future. Decisions made under risk showed different predictors. Performance on the IGT-ABCD for decisions made under risk was predicted by medium and high levels of explicit knowledge of the task, as well as by scores on the Disorderliness subscale and the degree of Stroop interference. By contrast, IGT-EFGH results were only associated with self-report impulsivity measures. CONCLUSIONS: Decision making in PG involves distinct patterns of deficits, and the predictors differ depending on the reinforcement schedule. Decisions made under risk on the IGT-ABCD are associated with explicit knowledge, executive functions and impulsivity traits related to conscious awareness and control processes. On the IGT-EFGH, however, only impulsivity traits predict decision making.

An App-Based Intervention for Pediatric Weight Management: Pre-Post Acceptability and Feasibility Trial.

BACKGROUND: A multidisciplinary approach to weight management is offered at tier 3 pediatric weight management services in the United Kingdom. Encouraging dietary change is a major aim, with patients meeting with dieticians, endocrinologists, psychologists, nurse specialists, and social workers on average every other month. OBJECTIVE: This research sought to trial an inhibitory control training smartphone app-FoodT-with the clinic population of a pediatric weight management service. FoodT has shown positive impacts on food choice in adult users, with resulting weight loss. It was hoped that when delivered as an adjunctive treatment alongside the extensive social, medical, psychological, and dietetic interventions already offered at the clinic, the introduction of inhibitory control training may offer patients another tool that supports eating choice. In this feasibility trial, recruitment, retention, and app use were the primary outcomes. An extensive battery of measures was included to test the feasibility and acceptability of these measures for future powered trials. METHODS: FoodT was offered to pediatric patients and their parents during a routine clinic appointment, and patients were asked to use the app at home every day for the first week and once per week for the rest of the month. Feasibility and acceptability were measured in terms of recruitment, engagement with the app, and retention to the trial. A battery of psychometric tests was given before and after app use to assess the acceptability of collecting data on changes to food choices and experiences that would inform future trial work. RESULTS: A total of 12 children and 10 parents consented (22/62, 35% of those approached). Further, 1 child and no parents achieved the recommended training schedule. No participants completed the posttrial measures. The reasons for not wanting to be recruited to the trial included participants not considering their weight to be connected to eating choices and not feeling that the app suited their needs. No reasons are known for noncompletion. CONCLUSIONS: It is unclear whether the intervention itself or the research processes, including the battery of measures, prevented completion. It is therefore difficult to make any decisions as to the value that the app has within this setting. Important lessons have been learned from this research that have potential broad relevance, including the importance of co-designing interventions with service users and avoiding deterring people from early-stage participation in extensive data collection.

"It helps me to stay on the right path, rather than give in": Mixed-method process evaluation of the ImpulsePal app-based intervention for weight management.

Background: Empirical research indicates that impulsive processes that operate below conscious monitoring can undermine peoples' attempts to change behaviour patterns, especially those that have become habitual. This may, therefore, be a serious challenge for those trying to lose weight. A novel smartphone app-based intervention (ImpulsePal) offers practical strategies to manage impulsive urges to facilitate reductions in the consumption of energy-dense processed food and overeating. Aim: This process evaluation of ImpulsePal aimed to explore what was delivered/received and used, mechanisms of action, and potential contextual factors impacting intervention engagement and outcomes. Methods: A mixed-methods process evaluation, with composite analysis of the quantitative (app usage statistics) and qualitative data (semi-structured interviews), was conducted alongside a feasibility randomised controlled trial with individuals with a body mass index of at least 25 kg/m2 who wanted to lose weight. Results: Of 58 participants receiving ImpulsePal, 56 had successfully shared app usage statistics, and 36 (62%) were interviewed. Although usage statistics indicated reductions in the use of some features, interviews indicated that participants were still using app-recommended strategies without requiring them to open ImpulsPal. Overall, interviews highlighted that participants valued having access to in-the-moment support, felt more aware of their own eating behaviour and influences on it, and felt an increased ability to avoid and reconceptualise, in-the-moment temptations. Conclusion: This process evaluation offers support for a logic model suggesting that impulse management, using ImpulsePal, can promote healthier eating among those motivated to lose weight. It also highlights the necessity of using multimodal methods to explore the delivery and use of digital interventions.

The Effect of Intermittent Fasting on Appetite: A Systematic Review and Meta-Analysis.

Previously, narrative reviews have considered the effects of intermittent fasting on appetite. One suggestion is that intermittent fasting attenuates an increase in appetite that typically accompanies weight loss. Here, we conducted the first systematic review and meta-analysis to quantify the effects of intermittent fasting on appetite, when compared to a continuous energy restriction intervention. Five electronic databases and trial registers were searched in February 2021 and February 2022. Abstracts (N = 2800) were screened and 17 randomized controlled trials (RCTs), consisting of a variety of intermittent fasting regimes, met our inclusion criteria. The total number of participants allocated to interventions was 1111 and all RCTs were judged as having either some concerns or a high risk of bias (Cochrane RoB 2.0 tool). Random effects meta-analyses were conducted on change-from-baseline appetite ratings. There was no clear evidence that intermittent fasting affected hunger (WMD = -3.03; 95% CI [-8.13, 2.08]; p = 0.25; N = 13), fullness (WMD = 3.11; 95% CI [-1.46, 7.69]; p = 0.18; N = 10), desire to eat (WMD = -3.89; 95% CI [-12.62, 4.83]; p = 0.38; N = 6), or prospective food consumption (WMD = -2.82; 95% CI [-3.87, 9.03]; p = 0.43; N = 5), differently to continuous energy restriction interventions. Our results suggest that intermittent fasting does not mitigate an increase in our drive to eat that is often associated with continuous energy restriction.

Nucleus accumbens response to food cues predicts subsequent snack consumption in women and increased body mass index in those with reduced self-control.

Individuals have difficulty controlling their food consumption, which is due in part to the ubiquity of tempting food cues in the environment. Individual differences in the propensity to attribute incentive (motivational) salience to and act on these cues may explain why some individuals eat more than others. Using fMRI in healthy women, we found that food cue related activity in the nucleus accumbens, a key brain region for food motivation and reward, was related to subsequent snack food consumption. However, both nucleus accumbens activation and snack food consumption were unrelated to self-reported hunger, or explicit wanting and liking for the snack. In contrast, food cue reactivity in the ventromedial prefrontal cortex was associated with subjective hunger/appetite, but not with consumption. Whilst the food cue reactivity in the nucleus accumbens that predicted snack consumption was not directly related to body mass index (BMI), it was associated with increased BMI in individuals reporting low self-control. Our findings reveal a neural substrate underpinning automatic environmental influences on consumption in humans and demonstrate how self-control interacts with this response to predict BMI. Our data provide support for theoretical models that advocate a 'dual hit' of increased incentive salience attribution to food cues and poor self-control in determining vulnerability to overeating and overweight.

The relationship between meat disgust and meat avoidance-A chicken-and-egg problem.

Feelings of disgust toward meat have been researched for at least 30 years, but so far the causal relationship that may link meat disgust and meat consumption has remained elusive. Two possible pathways have been proposed in previous literature: the more common pathway seems to be that meat disgust is developed after a transition to vegetarianism, potentially via the process of moralization and recruitment of (moral) disgust. Other accounts suggest the existence of a second pathway in which disgust initiates the avoidance of meat and this can be explained by existing theories of disgust functioning as a pathogen avoidance mechanism and meat serving as a pathogen cue. However, the evidence base for either relationship remains thin and to our knowledge no research has examined whether temporary meat abstention can lead to increases in meat disgust, as the first pathway suggests. We measured meat disgust and meat intake in n = 40 meat eaters before and after attempting a meat-free diet for 1 month (while taking part in the annual vegan campaign Veganuary). Although most participants lapsed to eating meat during this period, we found that reductions in meat intake during the month were predictive of increases in meat disgust afterwards. This supports the view that meat disgust is expressed as a result of meat avoidance in meat eaters. Implications for theoretical understanding of the relationship between meat disgust and meat avoidance, as well as the development of disgust based interventions are discussed.

The impact of COVID-19 on the eating habits of families engaged in a healthy eating pilot trial: a thematic analysis.

BACKGROUND: The eating habits of children and adults have been impacted by the COVID-19 pandemic, with evidence of increases in snacking and emotional eating, including eating to relieve boredom. We explored the experiences of families with children aged 4-8 years who had recently participated in a healthy eating pilot trial when the first national lockdown began in England. METHODS: Eleven mothers were interviewed in April and May 2020. Interview questions were developed based on the COM-B model of behaviour. Four main themes were constructed using inductive thematic analysis. RESULTS: The first theme related to an initial panic phase, in which having enough food was the primary concern. The second related to ongoing challenges during the lockdown, with sub-themes including difficulties accessing food, managing children's food requests and balancing home and work responsibilities. The perception that energy-dense foods met families' needs during this time led to increased purchasing of (and thus exposure to) energy-dense foods. In the third theme, families described a turning point, with a desire to eat a healthier diet than they had in the early stages of the lockdown. Finally, in the fourth theme, families reported a number of strategies for adapting and encouraging a balanced diet with their children. CONCLUSIONS: Our results suggest that even if parents have the capability (e.g. knowledge) and motivation to provide a healthy diet for their family, opportunity challenges (e.g. time, access to resources, environmental stressors) mean this is not always practical. Healthy eating interventions should not assume parents lack motivation and should be sensitive to the context within which parents make feeding decisions.