Examination of food reward and energy intake under laboratory and free-living conditions in a trait binge eating subtype of obesity

Do eating behavior traits predict energy intake and body mass index? A systematic review and meta-analysis

At present, it is unclear whether eating behavior traits (EBT) predict objectively measured short-term energy intake (EI) and longer-term energy balance as estimated by body mass index (BMI). This systematic review examined the impact of EBT on BMI and laboratory-based measures of EI in adults ( ≥ 18 years) in any BMI category, excluding self-report measures of EI. Articles were searched up until 28th October 2021 using MEDLINE, PsycINFO, EMBASE and Web of Science. Sixteen EBT were identified and the association between 10 EBT, EI and BMI were assessed using a random-effects meta-analysis. Other EBT outcomes were synthesized qualitatively. Risk of bias was assessed with the mixed methods appraisal tool. A total of 83 studies were included (mean BMI = 25.20 kg/m² , mean age = 27 years and mean sample size = 70). Study quality was rated moderately high overall, with some concerns in sampling strategy and statistical analyses. Susceptibility to hunger (n = 6) and binge eating (n = 7) were the strongest predictors of EI. Disinhibition (n = 8) was the strongest predictor of BMI. Overall, EBT may be useful as phenotypic markers of susceptibility to overconsume or develop obesity (PROSPERO: CRD42021288694).

Exploring acute and non-specific effects of mobile app-based response inhibition training on food evaluation and intake

Previous studies have demonstrated that response inhibition training can modify the appeal of palatable and energy-dense foods, thus serving as a potential intervention for weight management, via changes in food selection and intake. However, empirical findings of efficacy have been inconsistent across studies due to heterogenous approaches to measuring salient appetitive outcomes, training implementation strategies, and sample recruitment. Systematic assessment of both affective and motivational components of food reward may help characterise to what extent devaluation can be generalised to nutritionally similar foods post-training. In this mixed factorial experiment, a non-clinical, adult sample completed time-matched single sessions with mobile app-based response inhibition training and control tasks of short (12 min; n = 27) or long (20 min; n = 25) duration. Participants were assessed on two discrete facets of food reward pre- and post-training: pleasure (i.e., explicit liking) and desire (i.e., implicit wanting) for non-specific (i.e., novel) food stimuli differing in energy-density. Consumption of snacks categorised by energy density was also assessed in a laboratory ad libitum taste test post-training. No significant differences were found between intervention and control sessions on explicit liking or implicit wanting for non-specific energy-dense foods. Moreover, participants ate a similar volume of snack foods during both sessions. Training duration did not significantly moderate differences between intervention and control sessions in primary outcomes. Variance between intervention and control sessions in chocolate intake and frequency of choice for energy-dense foods, but not explicit liking, was associated with a higher BMI. Methodological and theoretical implications for appropriate intervention implementation and underlying mechanisms, respectively, are discussed.

The impact of 16-h heat exposure on appetite and food reward in adults

Heat exposure is thought to reduce energy intake (EI) but studies are sparse and results not always concordant. The aim of this study was to examine whether a 16-h exposure to 32 °C leads to reduced EI compared to a control session (22 °C) and whether modifications in appetite sensations or food reward are implied. Sixteen healthy, lean, and active participants (9 women and 7 men, 25 ± 5 yo, body mass index: 22.0 ± 2.4 kg.m^-2) were passively exposed to two different thermal temperatures from 4:00 pm to 8:00 am under controlled conditions. Hunger and thirst scores were regularly assessed using visual analogue scales. A fixed dinner meal (3670 ± 255 kJ) was consumed at 7:30 pm and an ad libitum breakfast buffet (20 foods/drinks varying in temperature, fat, and carbohydrate content) at 7:30 am. Components of reward (explicit liking [EL] and implicit wanting [EI]) for fat and sweet properties of food were assessed before each meal using the Leeds Food Preference Questionnaire (LFPQ). Ad libitum EI at breakfast did not differ between sessions (2319 ± 1108 vs 2329 ± 1141 kJ, in 22 and 32 °C sessions, respectively; p = 0.955). While thirst scores were higher in the 32 than the 22 °C session (p < 0.001), hunger scores did not differ (p = 0.580). EL and IW for high fat foods relative to low fat foods were decreased in 32 compared to 22 °C before dinner and breakfast (p < 0.001 for all). Although EI and hunger were not affected by a 16-h exposure to heat, modifications in food reward suggested a reduction in the preference of high-fat foods. Future research should investigate whether reduced EI in response to heat exposure is due to spontaneous selection of low-fat foods rather than altered appetite sensations.

Predicting Food Intake from Food Reward and Biometric Responses to Food Cues in Adults with Normal Weight Using Machine Learning

BACKGROUND

Eating behaviors are determined by a complex interplay between behavioral and physiologic signaling occurring before, during, and after eating.

OBJECTIVES

The aim was to explore how selected behavioral and physiologic variables separately and grouped together predicted intake of 8 different foods.

METHODS

One hundred adults with normal weight performed a food preference task combined with biometric measurements (the Steno Biometric Food Preference Task) in the fasting state. The task measured food reward as well as biometric (eye tracking, electrodermal activity, and facial expressions) responses to images of foods varying in fat content and taste. Energy intake from an ad libitum buffet of the same 8 foods as assessed in the preference task was subsequently assessed. A mixed-effects random forest approach was applied to explore how individual and combined measures of food reward and biometric responses predicted energy intake of the 8 single foods. The performance of the different prediction models was compared with the predictions from a linear model including only an intercept (naïve model) using bootstrap cross-validation.

RESULTS

Participants had a median [IQR] intake of 369 kJ [126-472 kJ] per food. Combined or separate measures of food reward or biometric responses did not predict energy intake better than the naïve model.

CONCLUSIONS

We did not find that the reward or biometric responses to food cues assessed in a clinical setting were useful in predicting energy intake of single foods. However, this study provides a framework in the field of behavioral nutrition for applying machine learning with a focus on individual predictions. This is necessary on the road toward personalized nutrition and provides great potential for handling complex data with multiple variables.This trial was registered at clinicaltrials.gov as NCT03986619.

Hyper-palatable food consumption during binge-eating episodes: A comparison of intake during binge eating and restricting

OBJECTIVE

The study aim was to elucidate the degree to which hyper-palatable foods (HPF) are consumed during binge episodes compared to restricting episodes, and to test the association between HPF intake during each episode and respective episode frequency.

METHOD

This study was a secondary analysis of data from a larger study on eating disorders. The present sample included adults (N = 147, 83% women) diagnosed with sub-threshold (41%) or full-threshold (59%) bulimia nervosa (BN). Foods consumed during binge and restricting episodes were assessed using the Eating Pathology Symptoms Inventory-Clinician Rated Version. A standardized definition of HPF developed previously was applied to foods consumed during binge and restricting episodes. A Wilcoxon matched-pairs signed-rank test was used to test the difference between total caloric intake from HPF (KcalHPF) and percentage of caloric intake from HPF (PercHPF) during binge episodes relative to restricting episodes. Four linear regression models tested HPF intake (KcalHPF and PercHPF) during both episode types (binge and restricting) as predictors of respective episode frequency.

RESULTS

There was a significant difference between median KcalHPF (1846.6 vs. 279.6; Z = -13.38, p < .001) and PercHPF during binge compared to restricting episodes (95% vs. 61%; Z = -7.35, p < .001). Regression analyses demonstrated that KcalHPF during binge episodes was significantly associated with binge episode frequency (B = 0.002; p < .001), but not PercHPF (p = .287).

DISCUSSION

Results suggest that HPF may be primarily consumed during binge episodes among individuals with BN, and may be associated with greater binge-eating frequency.

PUBLIC SIGNIFICANCE

Findings from the current study support an underlying assumption of theoretical models of binge eating, suggesting that highly rewarding, hyper-palatable foods (HPF), may constitute the vast majority of energy intake during binge-eating episodes. Additionally, a substantial amount of energy intake from HPF may occur during restricting episodes among people with bulimia nervosa. Greater HPF intake during binge eating may also be associated with binge-eating severity.

Food Reward after a Traditional Inuit or a Westernised Diet in an Inuit Population in Greenland

The food availability and dietary behaviours in Greenland have changed with increasing Westernisation. Food reward is an important driver of food choice and intake, which has not previously been explored in the Arctic population. The aim of this study was to explore differences in food reward after a four-week intervention period with a traditional Inuit diet (TID) or Westernised diet (WD) in Inuit populations in Northern and Western Greenland. This cross-sectional analysis included 44 adults (n = 20 after TID and n = 24 after WD). We assessed the food reward components, explicit liking and implicit wanting, using the Leeds Food Preference Questionnaire under standardised conditions 60 min after drinking a glucose drink as part of an oral glucose tolerance test after four weeks following a TID or WD. The food intake was assessed using food frequency questionnaires. The intervention groups differed only in implicit wanting for high-fat sweet foods, with higher implicit wanting among the participants following TID compared to WD. Both groups had lower explicit liking and implicit wanting for sweet relative to savoury foods and for high-fat relative to low-fat foods. This exploratory study can guide future studies in Inuit populations to include measures of food reward to better understand food intake in the Arctic.

Stress Responsiveness and Emotional Eating Depend on Youngsters' Chronic Stress Level and Overweight

The persistent coexistence of stress and paediatric obesity involves interrelated psychophysiological mechanisms, which are believed to function as a vicious circle. Here, a key mechanistic role is assumed for stress responsiveness and eating behaviour. After a stress induction by the Trier Social Stress Test in youngsters (n = 137, 50.4% boys, 6–18 years), specifically those high in chronic stress level and overweight (partial η² = 0.03–0.07) exhibited increased stress vulnerability (stronger relative salivary cortisol reactivity and weaker happiness recovery) and higher fat/sweet snack intake, compared to the normal-weight and low-stress reference group. Stress responsiveness seems to stimulate unhealthy and emotional eating, i.e., strong cortisol reactivity was linked to higher fat/sweet snack intake (β = 0.22) and weak autonomic system recovery was linked to high total and fat/sweet snack intake (β = 0.2–0.3). Additionally, stress responsiveness acted as a moderator. As a result, stress responsiveness and emotional eating might be targets to prevent stress-induced overweight.

Negative Mood and Food Craving Strength Among Women with Overweight: Implications for Targeting Mechanisms Using a Mindful Eating Intervention

Objectives

When experiencing negative mood, people often eat to improve their mood. A learned association between mood and eating may cultivate frequent food cravings, detracting from health goals. Training in mindful eating may target this cycle of emotion-craving-eating by teaching individuals to manage urges when experiencing negative mood. We examined the impact of a mobile mindful eating intervention on the link between negative mood and food cravings among overweight women.

Methods

In a single-arm trial, participants (n = 64, M age = 46.1 years, M BMI = 31.5 kg/m²) completed ecological momentary assessments of negative mood and food cravings 3 times/day for 3 days pre- and post-intervention, as well as 1-month post-intervention. Using multilevel linear regression, we compared associations between negative mood and food craving strength at pre- vs. post-intervention (model 1) and post-intervention vs. 1-month follow-up (model 2).

Results

In model 1, negative mood interacted with time point (β =  − .20, SE = .09, p = .02, 95% CI [− .38, − .03]) to predict craving strength, indicating that the within-person association between negative mood and craving strength was significantly weaker at post-intervention (β = 0.18) relative to pre-intervention (β = 0.38). In model 2, negative mood did not interact with time point to predict craving strength (β = .13, SE = .09, p = .10, 95% CI − .03, .31]); the association did not significantly differ between post-intervention and 1-month follow-up.

Conclusions

Training in mindful eating weakened the mood-craving association from pre- to post-intervention. The weakened association remained at follow-up. Our findings highlight the mood-craving link as a target-worthy mechanism of mindful eating that should be assessed in clinical trials.

Trial Registration

NCT02694731

Supplementary Information

The online version contains supplementary material available at 10.1007/s12671-021-01760-z.

A review of effort-based decision-making in eating and weight disorders

Effort-based decision-making provides a framework to understand the mental computations estimating the amount of work ("effort") required to obtain a reward. The aim of the current review is to systematically synthesize the available literature on effort-based decision-making across the spectrum of eating and weight disorders. More specifically, the current review summarises the literature examining whether 1) individuals with eating disorders and overweight/obesity are willing to expend more effort for rewards compared to healthy controls, 2) if particular components of effort-based decision-making (i.e. risk, discounting) relate to specific binge eating conditions, and 3) how individual differences in effort and reward -processing measures relate to eating pathology and treatment measures. A total of 96 studies were included in our review, following PRISMA guidelines. The review suggests that individuals with binge eating behaviours 1) are more likely to expend greater effort for food rewards, but not monetary rewards, 2) demonstrate greater decision-making impairments under risk and uncertainty, 3) prefer sooner rather than delayed rewards for both food and money, and 4) demonstrate increased implicit 'wanting' for high fat sweet foods. Finally, individual differences in effort and reward -processing measures relating to eating pathology and treatment measures are also discussed.

The effect of transcranial direct current stimulation (tDCS) on food craving, reward and appetite in a healthy population

The ability to control hedonic appetite is associated with executive functioning, originating in the prefrontal cortex (PFC). These rewarding components of food can override homeostatic mechanisms, potentiating obesogenic behaviours. Indeed, those susceptible to overconsumption appear to have PFC hypo-activation. Transcranial direct current stimulation (tDCS) over the dorsolateral PFC (DLPFC) has been shown to reduce food craving and consumption, potentially via attenuating this reward response. We examined the effects of stimulation on food reward and craving using a healthy-weight cohort. This study is amongst the first to explore the effects of tDCS on explicit and implicit components of reward for different food categories. Twenty-one healthy-weight participants (24 ± 7 years, 22.8 ± 2.3 kg m^-2) completed two sessions involving double-blind, randomised and counterbalanced anodal or sham tDCS over the right DLPFC, at 2 mA for 20 min. Food craving (Food Craving Questionnaire-State), reward (Leeds Food Preference Questionnaire), and subjective appetite (100 mm visual analogue scales) were measured pre- and post-tDCS. Eating behaviour trait susceptibility was assessed using the Three Factor Eating Questionnaire-Short Form, Control of Eating Questionnaire, and Food Craving Questionnaire-Trait-reduced. Stimulation did not alter food craving, reward or appetite in healthy-weight participants who displayed low susceptibility to overconsumption, with low trait craving, good craving control, and low uncontrolled eating and emotional eating behaviour. Implicit and explicit reward were reliable measures of hedonic appetite, suggesting these are robust targets for future tDCS research. These findings suggest that applying tDCS over the DLPFC does not change food reward response in individuals not at risk for overconsumption, and future work should focus on those at risk of overconsumption who may be more responsive to the effects of tDCS on hedonic appetite.

Relationship between trait suggestibility and eating-related behaviors in overweight and obesity

Differences in trait suggestibility among those with obesity may help explain differential responses to weight-loss interventions. Ubiquitous advertising of unhealthy foods, weight-loss products that are not evidence-based, and myths regarding weight loss could be particularly sabotaging in individuals with high levels of suggestibility, with or at risk of developing obesity. This study explored relationships between suggestibility, body mass index (BMI), and self-reported eating-related behaviors that vary among those with obesity. A sample of ethnically diverse adults (N = 73) with a BMI ≥25 completed the Short Suggestibility Scale (SSS), Palatable Eating Motives Scale (PEMS), Binge Eating Scale (BES), Dutch Eating Behavior Questionnaire-Restraint (DEBQ-R), and Barratt Impulsiveness Scale (BIS). Impulsiveness was controlled in analyses due to its strong association with suggestibility. Analyses revealed that BMI was not related to SSS scores, consistent with studies using hypnotic-suggestibility scales. However, SSS scores were positively associated with eating caloric food more frequently for Reward, Social, and Conformity motives, and with greater actual dieting behavior, and binge eating. Suggestibility was not related to eating for Coping motives or effort to diet. If supported by future replications, knowledge of these associations could potentially help inform and tailor weight-loss interventions to protect those that may be most susceptible to adopting invalid messages and products.

Dissociating wanting and anticipated liking from consummatory liking in smokers with different levels of nicotine dependence

INTRODUCTION

Incentive Sensitisation theory suggests wanting and liking are dissociable concepts, with wanting, but not liking typically increasing with repeated drug use. Wanting is associated with anticipation of reward, whereas liking relates to pleasure derived from consummatory behaviour. However, numerous studies have conceptualised liking as an anticipatory cognition. This study explores whether levels of nicotine dependence differentially effect wanting and liking responses to smoking-related cues, and whether anticipated and consummatory liking are equivalent, and dissociable from wanting.

METHOD

Heavy (HS, mean = 16 cigarettes/day) and light non-daily (LS, mean = 2 cigarettes/day) smokers completed wanting and anticipated liking questionnaires pre-, immediately post-exposure to smoking-related and neutral cues and at session-end. Consummatory liking was measured post-session, immediately after smoking.

RESULTS

Wanting and anticipated liking responses were comparable. Smoking-related cues increased wanting and anticipated liking compared to neutral cues. This effect was maintained until session-end. No baseline differences were seen between HS and LS on wanting or anticipated liking, however after cue exposure, and at session-end, HS reported greater drug wanting and anticipated liking than LS. Conversely, HS and LS did not differ on consummatory liking. Analyses confirmed the relationship between wanting and anticipated liking was significantly stronger than wanting and consummatory liking or anticipated and consummatory liking.

CONCLUSIONS

Wanting and anticipated liking appear to be overlapping constructs assessing expectations of reward, that are dissociable from consummatory liking. Furthermore, heavier smoking increases drug wanting, but not smoking pleasure. Future attempts to dissociate these concepts should ensure liking is measured during/immediately after consumption.

Food Addiction: Implications for the Diagnosis and Treatment of Overeating

With the obesity epidemic being largely attributed to overeating, much research has been aimed at understanding the psychological causes of overeating and using this knowledge to develop targeted interventions. Here, we review this literature under a model of food addiction and present evidence according to the fifth edition of the Diagnostic and Statistical Manual (DSM-5) criteria for substance use disorders. We review several innovative treatments related to a food addiction model ranging from cognitive intervention tasks to neuromodulation techniques. We conclude that there is evidence to suggest that, for some individuals, food can induce addictive-type behaviours similar to those seen with other addictive substances. However, with several DSM-5 criteria having limited application to overeating, the term ‘food addiction’ is likely to apply only in a minority of cases. Nevertheless, research investigating the underlying psychological causes of overeating within the context of food addiction has led to some novel and potentially effective interventions. Understanding the similarities and differences between the addictive characteristics of food and illicit substances should prove fruitful in further developing these interventions.

Evaluation of the Influence of Raw Almonds on Appetite Control: Satiation, Satiety, Hedonics and Consumer Perceptions

Snack foods can be substantial contributors to daily energy intake, with different types of snacks exerting potentially different effects on satiety per calorie consumed. The present research compared the effect of consuming almonds as a mid-morning snack compared to an energy and weight-matched comparator snack (savoury crackers) or the equivalent weight of water (zero energy control). In a crossover design, 42 female participants (age: 26.0 ± 7.9, BMI: 22.0 ± 2.0) consumed a fixed breakfast then a mid-morning snack. Appetite, 24-h energy intake, food hedonics, and consumer perceptions of the snack foods were assessed under laboratory conditions. AUC analyses revealed a lower overall hunger drive after consuming almonds compared to crackers or water. There was no difference in 24-h energy intake in the almond compared to the cracker or the zero-energy control condition, however participants consumed more energy in the cracker condition compared to the zero-energy control condition. In addition, almonds suppressed hedonic preference (implicit wanting) for consuming high-fat foods and demonstrated a higher satiety quotient (SQ) than crackers. Almonds were perceived to have a more favourable consumer profile aligned with successful weight management. In conclusion, these findings demonstrate that in the context of a 24-h period of objectively measured energy intake, raw almonds are effective for controlling appetite compared to an energy matched alternative snack. This trial was registered at clinicaltrials.gov [NCT02480582].

Do restrained eaters show increased BMI, food craving and disinhibited eating? A comparison of the Restraint Scale and the Restrained Eating scale of the Dutch Eating Behaviour Questionnaire

Despite being used interchangeably, different measures of restrained eating have been associated with different dietary behaviours. These differences have impeded replicability across the restraint literature and have made it difficult for researchers to interpret results and use the most appropriate measure for their research. Across a total sample of 1731 participants, this study compared the Restraint Scale (RS), and its subscales, to the Dutch Eating Behaviour Questionnaire (DEBQ) across several traits related to overeating. The aim was to explore potential differences between these two questionnaires so that we could help to identify the most suitable measure as a prescreening tool for eating-related interventions. Results revealed that although the two measures are highly correlated with one another (rs = 0.73-0.79), the RS was more strongly associated with external (rs = -0.07 to 0.11 versus -0.18 to -0.01) and disinhibited eating (rs = 0.46 versus 0.31), food craving (rs = 0.12-0.27 versus 0.02-0.13 and 0.22 versus -0.06) and body mass index (rs = 0.25-0.34 versus -0.13 to 0.15). The results suggest that, compared to the DEBQ, the RS is a more appropriate measure for identifying individuals who struggle the most to control their food intake.

Dried fruit and public health - what does the evidence tell us?

A scientific workshop held in the UK explored the potential contribution of traditional dried fruits to public health, identified gaps in the evidence and addressed priorities for research. Presentations considered the categorisation and composition of dried fruits; dried fruit and gastrointestinal health; the polyphenol content of dried fruits and their potential contribution to health; dried fruit and appetite in relation to the psychology of snacking and obesity; dried fruit and dental health including its role as a snack; and conflicts in public health advice for dried fruits. A round table discussion explored the contribution of dried fruit to "five a day" fruit and vegetable intake and fibre intake, whether dried fruits have equivalence with fresh in terms of dietary advice, advice on snacking in relation to dental health and appetite control, informing the public about different types of dried fruits and avoiding consumer confusion, and future research requirements.

'Say no': a feasibility trial of a brief intervention to reduce instances of indulgent energy-intake episodes

The aim of this study is to examine the feasibility of a brief intervention to reduce instances of indulgent energy intake. Forty-five participants with a body mass index (BMI) ≥25 kg m-² were randomized to one of three groups for 8 weeks. The control group was asked to complete a questionnaire every 4 days, the self-monitoring group was given the same instructions but also asked to 'say no' to indulgences. The self-monitoring and feedback group was asked to do the same but in addition to send a photograph or description of that to which they had 'said no' and were then provided with feedback. All participants reported on indulgences for 7 days prospectively at baseline and 8-week follow-up. The follow-up rate was 80%; completion of questionnaires was 63% and 87 text messages were sent. The control group reduced their indulgences by 4.1 (SD 10.0), the self-monitoring group by 13.8 (SD 16.8) and self-monitoring and feedback group by 9.0 (SD 11.7) per week. All bar one, feasibility progression criteria were met and this was the return of the indulgence diaries during the intervention period. The study demonstrates the feasibility of a brief intervention to reduce the number of indulgences people ate. The progression criteria were met and areas of improvement are highlighted.

An Examination of Appetite and Disordered Eating in Active Crohn's Disease

BACKGROUND

Crohn's disease [CD] patients suffer from nutritional deficiencies when in active disease. We aim to examine calorific intake, macronutrient choice, and disordered eating behaviour in patients with active CD.

METHODS

CD patients with matched healthy volunteers [HV] were recruited. Active disease was defined by faecal calprotectin >250 µg/g, C-reactive protein 83.8 ± 47.1 mg/dL, or active disease seen on endoscopy or imaging. Symptoms were quantified by Harvey‑Bradshaw Index [HBI]. Calorific intake was assessed by 24-h dietary recall. Disordered eating was assessed using validated questionnaires: Binge Eating Scale [BES]; Power of Food Scale [PFS]; Control of Eating Questionnaire [CoEQ]; Dutch Eating Behaviour Questionnaire [DEBQ]; and Three Factor Eating Questionnaire [TFEQ].

RESULTS

Totals of 30 CD (18 male[M]:12 female [F], age 32.3 ± 2.19 years, body mass index [BMI] 24.9 ± 0.8) and 31 matched HV [19 M:12 F, age 32.8 ± 2.0 years, BMI 24.7 ± 0.5] were recruited. Mean faecal calprotectin was 1032.5 ± 176 µg/g, C-reactive protein 8.38 ± 4.71 mg/dL, and HBI 4.8 ± 1. There were no significant differences in calorific intake between groups. Protein intake was lower in the CD cohort [p = 0.03]. Hospital Anxiety and Depression score was higher [p = 0.01] and CoEQ-Positive Mood [p = 0.001] lower in CD. CD patients were characterised by higher BES [p = 0.01] and lower CoEQ Craving Control [p = 0.027], with greater craving for Sweet [p = 0.043] and Savoury [p = 0.021] foods. PFS food Present [p = 0.005], DEBQ Emotional [p =< 0.001], and External Eating [p = 0.022] were significantly higher than among HV.

CONCLUSIONS

Reduced protein consumption and more prevalent disordered eating behaviour traits were present in CD. Greater binge eating and decreased control of cravings may be attributed to lower mood and higher anxiety observed. Patients may benefit from stronger psychological support with firm dietetic advice for healthy eating.

Subjective feelings of appetite of wholegrain breakfasts evaluated under controlled, laboratory and 'at home' conditions

BACKGROUND

Appetite regulating properties of foods are usually investigated under laboratory conditions, whereas in real life, foods are consumed under at home conditions. The objective of this study was to compare the acute effects of breakfasts when tested in a laboratory condition and in an at home condition. Appetite regulating properties of two bread breakfasts and two cereal breakfasts were also compared.

SUBJECTS AND METHODS

In this randomized cross-over trial balanced for laboratory and at home test conditions, thirty-two women consumed five breakfasts, i.e. two bread breakfasts, two cereal breakfasts and one fried-egg breakfast. Visual analogue scales for measuring appetite were captured via an on-line scoring system and were analyzed as incremental area under the curve, as satiation phase and as satiety phase.

RESULTS

Location effects were limited to two small effects only. An overall location effect in hunger feelings was observed (p = 0.040), which occurred specifically during the short satiation period (p = 0.0002) where hunger feelings scored higher under laboratory conditions. Similarly, a location effect was observed for desire to eat (p = 0.001); this was again higher under laboratory conditions. No other location effects were observed. Bread breakfasts did not differ in their appetite regulating properties. The Steel Cut oatmeal breakfast was reported to be more satiating (p = 0.001) as compared to the ready-to-eat cereal.

CONCLUSIONS

Whereas the five breakfasts varied somewhat in their appetite regulating properties, evaluation under laboratory conditions overall did not result in different appetite scores compared to the at home conditions. This suggests that at home testing may be a useful alternative to laboratory test conditions for nutrition research.

Peripheral Endocannabinoid Responses to Hedonic Eating in Binge-Eating Disorder

Reward mechanisms are likely implicated in the pathophysiology of binge-eating behaviour, which is a key symptom of binge-eating disorder (BED). Since endocannabinoids modulate food-related reward, we aimed to investigate the responses of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) to hedonic eating in patients with BED. Peripheral levels of AEA and 2-AG were measured in 7 obese BED patients before and after eating favorite (hedonic eating) and non-favorite (non-hedonic eating) foods. We found that plasma levels of AEA progressively decreased after eating the non-favorite food and significantly increased after eating the favorite food, whereas plasma levels of 2-AG did not differ significantly between the two test conditions, although they showed a trend toward significantly different time patterns. The changes in peripheral AEA levels were positively correlated to the subjects’ sensations of the urge to eat and the pleasantness while eating the presented food, while changes in peripheral 2-AG levels were positively correlated to the subjects’ sensation of the pleasantness while eating the presented food and to the amount of food they would eat. These results suggest the occurrence of distinctive responses of endocannabinoids to food-related reward in BED. The relevance of such findings to the pathophysiology of BED remains to be elucidated.

Early improvement in food cravings are associated with long-term weight loss success in a large clinical sample

BACKGROUND

Food cravings are associated with dysregulated eating behaviour and obesity, and may impede successful weight loss attempts. Gaining control over food craving is therefore a component in the management of obesity. The current paper examined whether early changes in control over food craving (assessed using the Craving Control subscale on the Control of Eating Questionnaire (CoEQ)) was predictive of weight loss in four phase 3 clinical trials investigating a sustained-release combination of naltrexone/bupropion (NB) in obese adults. The underlying component structure of the CoEQ was also examined.

METHOD

In an integrated analysis of four 56-week phase 3 clinical trials, subjects completed the CoEQ and had their body weight measured at baseline and at weeks 8, 16, 28 and 56. All analyses were conducted on subjects who had complete weight and CoEQ measurements at baseline and week 56, and had completed 56 weeks of NB (n=1310) or placebo (n=736). A latent growth curve model was used to examine whether early changes in the CoEQ subscales were associated with decreases in weight loss over time. Confirmatory factor analysis (CFA) was used to determine the psychometric properties of the CoEQ.

RESULTS

The factor structure of the CoEQ was consistent with previous findings with a four-factor solution being confirmed: Craving Control, Positive Mood, Craving for Sweet and Craving for Savoury with good internal consistency (Cronbach's α=0.72-0.92). Subjects with the greatest improvement in Craving Control at week 8 exhibited a greater weight loss at week 56.

CONCLUSIONS

These findings highlight the importance of the experience of food cravings in the treatment of obesity and support the use of the CoEQ as a psychometric tool for the measurement of food cravings in research and the pharmacological management of obesity.

Trait and state binge eating predispose towards cocaine craving

Binge eating (BE) and drug seeking share similar behavioral features, including loss of control over consumption and compulsive seeking of the craved substance. Previous studies in animal models have demonstrated a complex interaction between 'state' BE, produced by intermittent access to a palatable diet, and 'trait' BE, a phenotypical proneness towards overeating. In the present study, we examined the relationship between state and trait BE and cocaine seeking. We used Otsuka Long Evans Tokushima Fatty rats, a genetic model for obesity that demonstrates BE-like behavior, and Long Evans Tokushima Otsuka controls. They received a schedule of limited access to a palatable diet (3 days/week or 5 days/week access to Ensure for a month). Next, they underwent cocaine self-administration training (1 mg/kg, 1 hour/day for 10 days) followed by extinction sessions (7 days). We found that the degree of BE-like behavior and the state and trait BE combination predicted cocaine craving patterns. Lower levels of dopamine D2 receptors in the prefrontal cortex were correlated with increased drug craving. Moreover, restricted access to an attractive diet was found to be a risk factor for heightened cocaine craving, particularly in trait binge eaters, as rats on the 3 days/week access schedule persistently failed to cease cocaine seeking throughout extinction. Hence, we postulate a joint role of state and trait BE as risk factors for heightened cocaine craving.

Binge abstinence is associated with reduced energy intake after treatment in patients with binge eating disorder and obesity

OBJECTIVE

Binge eating disorder (BED) is strongly associated with obesity and related medical and psychiatric morbidities. Cognitive behavioral therapy (CBT) has consistently been shown to reduce binge eating frequency and improve psychological functioning, as well as to produce abstinence rates of roughly 50%. This study examined the relationship between binge abstinence and dietary and psychological outcomes after CBT for BED.

METHODS

Fifty adult patients with BED received 6-month treatments using a combination of CBT and dietary counseling. Trained interviewers conducted two 24-hour dietary recall interviews on randomly selected days at baseline and at 6 months.

RESULTS

Participants had significant reductions in energy, macronutrient, and sugar intake and an increase in fruit intake. They reported significant reductions in BMI and binge eating frequency (from mean = 14.24 to mean = 1.90 binge eating episodes during the previous 28 days), as well as improvements in psychological functioning. Those who became binge abstinent reported eating roughly 400 fewer calories per day and experienced greater improvements in psychological functioning than those who did not.

CONCLUSIONS

Findings from this study suggest that individuals who achieve complete cessation from binge eating have significantly improved dietary and psychological outcomes that could potentially improve weight status, compared with those who continue to binge eat post-treatment.

Differing effects of high-fat or high-carbohydrate meals on food hedonics in overweight and obese individuals

Although the effects of dietary fat and carbohydrate on satiety are well documented, little is known about the impact of these macronutrients on food hedonics. We examined the effects of ad libitum and isoenergetic meals varying in fat and carbohydrate on satiety, energy intake and food hedonics. In all, sixty-five overweight and obese individuals (BMI=30·9 (sd 3·8) kg/m2) completed two separate test meal days in a randomised order in which they consumed high-fat/low-carbohydrate (HFLC) or low-fat/high-carbohydrate (LFHC) foods. Satiety was measured using subjective appetite ratings to calculate the satiety quotient. Satiation was assessed by intake at ad libitum meals. Hedonic measures of explicit liking (subjective ratings) and implicit wanting (speed of forced choice) for an array of HFLC and LFHC foods were also tested before and after isoenergetic HFLC and LFHC meals. The satiety quotient was greater after ad libitum and isoenergetic meals during the LFHC condition compared with the HFLC condition (P=0·006 and P=0·001, respectively), whereas ad libitum energy intake was lower in the LFHC condition (P<0·001). Importantly, the LFHC meal also reduced explicit liking (P<0·001) and implicit wanting (P=0·011) for HFLC foods compared with the isoenergetic HFLC meal, which failed to suppress the hedonic appeal of subsequent HFLC foods. Therefore, when coupled with increased satiety and lower energy intake, the greater suppression of hedonic appeal for high-fat food seen with LFHC foods provides a further mechanism for why these foods promote better short-term appetite control than HFLC foods.

Responses of peripheral endocannabinoids and endocannabinoid-related compounds to hedonic eating in obesity

PURPOSE

Hedonic eating occurs independently from homeostatic needs prompting the ingestion of pleasurable foods that are typically rich in fat, sugar and/or salt content. In normal weight healthy subjects, we found that before hedonic eating, plasma levels of 2-arachidonoylglycerol (2-AG) were higher than before nonhedonic eating, and although they progressively decreased after food ingestion in both eating conditions, they were significantly higher in hedonic eating. Plasma levels of anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), instead, progressively decreased in both eating conditions without significant differences. In this study, we investigated the responses of AEA, 2-AG, OEA and PEA to hedonic eating in obese individuals.

METHODS

Peripheral levels of AEA, 2-AG, OEA and PEA were measured in 14 obese patients after eating favourite (hedonic eating) and non-favourite (nonhedonic eating) foods in conditions of no homeostatic needs.

RESULTS

Plasma levels of 2-AG increased after eating the favourite food, whereas they decreased after eating the non-favourite food, with the production of the endocannabinoid being significantly enhanced in hedonic eating. Plasma levels of AEA decreased progressively in nonhedonic eating, whereas they showed a decrease after the exposure to the favourite food followed by a return to baseline values after eating it. No significant differences emerged in plasma OEA and PEA responses to favourite and non-favourite food.

CONCLUSION

Present findings compared with those obtained in our previously studied normal weight healthy subjects suggest deranged responses of endocannabinoids to food-related reward in obesity.

Weak Satiety Responsiveness Is a Reliable Trait Associated with Hedonic Risk Factors for Overeating among Women

Some individuals exhibit a weak satiety response to food and may be susceptible to overconsumption. The current study identified women showing consistently low or high satiety responses to standardised servings of food across four separate days and compared them on behavioural, psychological and physiological risk factors for overeating and future weight gain. In a crossover design, 30 female participants (age: 28.0 ± 10.6; body mass index (BMI): 23.1 ± 3.0) recorded sensations of hunger in the post-prandial period following four graded energy level breakfasts. Satiety quotients were calculated to compare individuals on satiety responsiveness across conditions. Body composition, resting metabolic rate (RMR), energy intake, food reward and craving, and eating behaviour traits were assessed under controlled laboratory conditions. A distinct low satiety phenotype (LSP) was identified with good consistency across separate study days. These individuals had a higher RMR, greater levels of disinhibition and reported feeling lower control over food cravings. Further, they consumed more energy and exhibited greater wanting for high-fat food. The inverse pattern of characteristics was observed in those exhibiting a consistently high satiety phenotype (HSP). Weak satiety responsiveness is a reliable trait identifiable using the satiety quotient. The LSP was characterised by distinct behavioural and psychological characteristics indicating a risk for overeating, compared to HSP.

Eating tasty food to cope. Longitudinal association with BMI

The goals of this study were to determine if a change in certain motives to eat highly palatable food, as measured by the Palatable Eating Motives Scale (PEMS), could predict a change in body mass index (BMI) over time, to assess the temporal stability of these motive scores, and to test the reliability of previously reported associations between eating tasty foods to cope and BMI. BMI, demographics, and scores on the PEMS and the Binge Eating Scale were obtained from 192 college students. Test-retest analysis was performed on the PEMS motives in groups varying in three gap times between tests. Regression analyses determined what PEMS motives predicted a change in BMI over two years. The results replicated previous findings that eating palatable food for Coping motives (e.g., to forget about problems, reduce negative feelings) is associated with BMI. Test-retest correlations revealed that motive scores, while somewhat stable, can change over time. Importantly, among overweight participants, a change in Coping scores predicted a change in BMI over 2 years, such that a 1-point change in Coping predicted a 1.76 change in BMI (equivalent to a 10.5 lb. change in body weight) independent of age, sex, ethnicity, and initial binge-eating status (Cohen's f(2) effect size = 1.44). The large range in change of Coping scores suggests it is possible to decrease frequency of eating to cope by more than 1 scale point to achieve weight losses greater than 10 lbs. in young overweight adults, a group already at risk for rapid weight gain. Hence, treatments aimed specifically at reducing palatable food intake for coping reasons vs. for social, reward, or conformity reasons, should help achieve a healthier body weight and prevent obesity if this motive-type is identified prior to significant weight gain.

Motives for eating tasty foods associated with binge-eating. Results from a student and a weight-loss seeking population

The aim of this study was to use the Palatable Eating Motives Scale (PEMS) to determine if and what motives for eating tasty foods (e.g., junk food, fast food, and desserts) are associated with binge-eating in two diverse populations. BMI and scores on the PEMS, Yale Food Addiction Scale (YFAS), and Binge-eating Scale (BES) were obtained from 247 undergraduates at the University of Alabama at Birmingham (UAB) and 249 weight-loss seeking patients at the UAB EatRight program. Regression analyses revealed that eating tasty foods to forget worries and problems and help alleviate negative feelings (i.e., the 4-item Coping motive) was associated with binge-eating independently of any variance in BES scores due to sex, age, ethnicity, BMI, other PEMS motives, and YFAS scores in both students (R² = .57) and patients (R² = .55). Coping also was associated with higher BMI in students (p < 0.01), and in patients despite their truncated BMI range (p < 0.05). Among students, the motives Conformity and Reward Enhancement were also independently associated with binge-eating. For this younger sample with a greater range of BES scores, eating for these motives, but not for Social ones, may indicate early maladaptive eating habits that could later develop into disorders characterized by binge-eating if predisposing factors are present. Thus, identifying one's tasty food motive or motives can potentially be used to thwart the development of BED and obesity, especially if the motive is Coping. Identifying one's PEMS motives should also help personalize conventional treatments for binge-eating and obesity toward improved outcomes.

Fasting Leptin Is a Metabolic Determinant of Food Reward in Overweight and Obese Individuals during Chronic Aerobic Exercise Training

Changes in food reward have been implicated in exercise-induced compensatory eating behaviour. However, the underlying mechanisms of food reward, and the physiological correlates of exercise-induced changes in food reward, are unknown. Methods. Forty-six overweight and obese individuals completed 12 weeks of aerobic exercise. Body composition, food intake, and fasting metabolic-related hormones were measured at baseline, week six, and postintervention. On separate days, the reward value of high-and-low-fat food (explicit liking and implicit wanting) was also assessed at baseline, week six, and postintervention. Results. Following the intervention, FM, FFM, and VO2peak improved significantly, while fasting leptin decreased. However, food intake or reward did not change significantly. Cross-sectional analyses indicated that FM (P = 0.022) and FFM (P = 0.046) were associated with explicit liking for high-fat food, but implicit wanting was associated with FM only (P = 0.005). Fasting leptin was associated with liking (P = 0.023) and wanting (P = 0.021) for high-fat food. Furthermore, a greater exercise-induced decline in fasting leptin was associated with increased liking (P = 0.018). Conclusion. These data indicate that food reward has a number of physiological correlates. In particular, fasting leptin appears to play an active role in mediating food reward during exercise-induced weight loss.