Food Cue Reactivity Research Articles

Approach bias modification training in bulimia nervosa and binge-eating disorder: A pilot randomized controlled trial.

Bulimia nervosa (BN) and binge-eating disorder (BED) are associated with poorly controlled approach behavior toward food resulting in binge eating. Approach bias modification (ABM) may reduce these automatic action tendencies (i.e., approach bias) toward food and may thus decrease binge eating and related symptoms. A total of 56 patients with BN/BED participated in this double-blind, randomized controlled trial (RCT) comparing real and sham ABM. The real ABM condition adopted an implicit learning paradigm in which participants were trained to show avoidance behavior in response to food cues. Participants in the sham condition used a similar task but were not trained to avoid food cues. Both conditions comprised 10 training sessions within 4 weeks. Participants in both groups experienced significant reductions in binge eating, eating disorder symptoms, trait food craving, and food cue reactivity. Real ABM tended to result in greater reductions in eating disorder symptoms than sham ABM. Food intake, approach bias, and attention bias toward food did not change. This is the first RCT on ABM in eating disorders. The findings provide limited support for the efficacy of ABM in BN/BED and pose questions regarding its active ingredients and its usefulness as a stand-alone treatment for eating disorders.

Exposure therapy vs lifestyle intervention to reduce food cue reactivity and binge eating in obesity: A pilot study

Background and objectivesLearning models of overeating predict that exposure therapy is effective in reducing food cue reactivity and overeating. This pilot study tested an eight-session exposure therapy aimed at inhibitory learning vs. an active control condition aimed at lifestyle improvement for obesity (treatment-as-usual). Main outcomes are snacking behavior, eating psychopathology, food cue reactivity, and weight loss. Change in overeating expectancies was assessed as mediator for outcomes, and the associations between habituation of eating desires and outcomes were investigated in the exposure condition. Sleep quality was investigated as moderator for outcomes. Methods45 overweight women were randomly assigned to the exposure intervention or control condition. The main outcomes, overeating expectancies and sleep quality were re-assessed at post-treatment and three-month follow-up. Habituation of eating desires was measured during exposure sessions. ResultsCompared to the control intervention, exposure led to a significantly stronger reduction in snacking behavior of exposed foods, though this effect did not generalize to non-exposed foods, and stronger binge eating frequency. The exposure condition lost significantly more weight at post-treatment and follow-up than the lifestyle condition. Changes of expectancies mediated the effect of condition on kcal consumption of exposed foods, while habituation during exposure was not related to better treatment outcome. Sleep quality did not moderate the effect of condition on treatment outcome. LimitationsSmall sample size and limited follow-up period. ConclusionsThis short exposure therapy reduced snacking behavior, binge eating and weight more than a lifestyle intervention and is therefore a recommendable intervention for obesity and overeating disorders.

Food Cue Reactivity and the Brain-Heart Axis During Cognitive Stress Following Clinically Relevant Weight Loss

Successful weight loss maintainers are more vulnerable to stress induced eating. The aim of our study was to determine what effect an attention-demanding cognitive performance task had on brain-heart reactivity to visual food cues in women who maintained clinically relevant weight loss vs. women who had never weight cycled. A clinical weight loss group (CWL, n = 17) and a BMI-matched control group (CTL, n = 23) completed modified Stroop tasks that either included high calorie food pictures (Food Stroop) or excluded food cues (Office Stroop). ECG, breathing rate, and EEG were recorded. CWL participants: The Eating Restraint scores (Three Factor Eating Questionnaire) of the CWL participants correlated negatively with their heart rates recorded during the Food Stroop task (r = 0.62, p < 0.01). There was no such relationship in CTL participants. The P200 latencies in CWL participants evoked by the Stroop color-word cues at the C3 electrode were positively correlated to the log high frequency power in their cardiac spectrograms during the Food Stroop (r = 0.63, p < 0.02). There were no such relationships in the Office Stroop task nor in CTL participants. Combined Groups: Participants' heart rates were significantly lower (p < 0.05) and their RMSSD values and the log Total Power in their cardiac spectrograms were significantly greater during the Food Stroop vs. Office Stroop (p < 0.01, Bonferroni corrected). In conclusion Eating Restraint scores in CWL participants correlated with their Stroop heart rates, while the P200 latencies evoked by the Stroop cues correlated with the log high frequency power in their cardiac spectrograms (marker of cardiac vagal activation) during the Food Stroop task. This provides evidence that even 12 months after successful weight loss maintenance the cardiac ANS reactivity to food cues while completing a cognitive performance test was still different to that in individuals of normal weight who never weight cycled. Across all participants the cardiac ANS reactivity evoked by performing the Stroop task was lowered by food cues suggesting that the dampening effect of food cues on cardiac ANS reactivity may be one of the drivers of ‘stress induced' eating.

Efficacy of weight loss intervention can be predicted based on early alterations of fMRI food cue reactivity in the striatum

Increased fMRI food cue reactivity in obesity, i.e. higher responses to high- vs. low-calorie food images, is a promising marker of the dysregulated brain reward system underlying enhanced susceptibility to obesogenic environmental cues. Recently, it has also been shown that weight loss interventions might affect fMRI food cue reactivity and that there is a close association between the alteration of cue reactivity and the outcome of the intervention. Here we tested whether fMRI food cue reactivity could be used as a marker of diet-induced early changes of neural processing in the striatum that are predictive of the outcome of the weight loss intervention. To this end we investigated the relationship between food cue reactivity in the striatum measured one month after the onset of the weight loss program and weight changes obtained at the end of the six-month intervention. We observed a significant correlation between BMI change measured after six months and early alterations of fMRI food cue reactivity in the striatum, including the bilateral putamen, right pallidum, and left caudate. Our findings provide evidence for diet-induced early alterations of fMRI food cue reactivity in the striatum that can predict the outcome of the weight loss intervention.

Using neuroimaging to investigate the impact of Mandolean\xae training in young people with obesity: a pilot randomised controlled trial

BackgroundSlowing eating rate using the Mandolean® previously helped obese adolescents to self-select smaller portion sizes, with no reduction in satiety, and enhanced ghrelin suppression. The objective of this pilot, randomised trial was to investigate the neural response to food cues following Mandolean® training using functional Magnetic Resonance Imaging (fMRI), and measures of ghrelin, PYY, glucose and self-reported appetite.MethodTwenty-four obese adolescents (11–18 years; BMI ≥ 95th centile) were randomised (but stratified by age and gender) to receive six-months of standard care in an obesity clinic, or standard care plus short-term Mandolean® training. Two fMRI sessions were conducted: at baseline and post-intervention. These sessions were structured as an oral glucose tolerance test, with food cue-reactivity fMRI, cannulation for blood samples, and appetite ratings taken at baseline, 30 (no fMRI), 60 and 90 min post-glucose. As this was a pilot trial, a conservative approach to the statistical analysis of the behavioural data used Cliff’s delta as a non-parametric measure of effect size between groups. fMRI data was analysed using non-parametric permutation analysis (RANDOMISE, FSL).ResultsFollowing Mandolean® training: (i) relatively less activation was seen in brain regions associated with food cue reactivity after glucose consumption compared to standard care group; (ii) 22% reduction in self-selected portion size was found with no reduction in post-meal satiety. However, usage of the Mandolean® by the young people involved was variable and considerably less than planned at the outset (on average, 28 meals with the Mandolean® over six-months).ConclusionThis pilot trial provides preliminary evidence that Mandolean® training may be associated with changes in how food cues in the environment are processed, supporting previous studies showing a reduction in portion size with no reduction in satiety. In this regard, the study supports targeting eating behaviour in weight-management interventions in young people. However, given the variable usage of the Mandolean® during the trial, further work is required to design more engaging interventions reducing eating speed.Trial registrationISRCTN, ISRCTN84202126, retrospectively registered 22/02/2018.

Anterior insula activity regulates the associated behaviors of high fat food binge intake and cue reactivity in male rats

Binge eating episodes are characterized by uncontrollable, excessive intake of food and are associated with binge eating disorder and some subtypes of obesity. One factor thought to contribute to binge episodes is a high level of reactivity to food-associated cues (i.e., cue reactivity). The insula is a neural node poised to regulate both binge eating and cue reactivity because of its prominent role in interpretation of internal and external cues. This work established a positive association between high fat food (HFF) binge intake and cue reactivity in male rats. Furthermore, we demonstrated that activation of the anterior insula suppressed both HFF binge intake and cue reactivity, without altering homeostatic intake of food. We further show that attenuation of HFF binge intake and cue reactivity is not due to decreased food-reward efficacy or deficits in motivation. Together, these data establish a key role for the anterior insula in the control of binge eating related-behaviors and support novel avenues for the treatment of binge eating.

Neurocognitive and Hormonal Correlates of Voluntary Weight Loss in Humans

Insufficient responses to hypocaloric diets have been attributed to hormonal adaptations that override self-control of food intake. We tested this hypothesis by measuring circulating energy-balance hormones and brain functional magnetic resonance imaging reactivity to food cues in 24 overweight/obese participants before, and 1 and 3months after starting a calorie restriction diet. Increased activity and functional connectivity in prefrontal regions at month 1 correlated with weight loss at months 1 and 3. Weight loss was also correlated with increased plasma ghrelin and decreased leptin, and these changes were associated with food cue reactivity in reward-related brain regions. However, the reduction in leptin did not counteract weight loss; indeed, it was correlated with further weight loss at month 3. Activation in prefrontal regions associated with self-control could contribute to successful weight loss and maintenance. This work supports the role of higher-level cognitive brain function in body-weight regulation in humans.

Food cue-induced craving in individuals with bulimia nervosa and binge-eating disorder.

Individuals with bulimia nervosa (BN) or binge-eating disorder (BED) experience more frequent and intense food cravings than individuals without binge eating. However, it is currently unclear whether they also show larger food cue-induced increases in craving (i.e., food cue reactivity) than those without binge eating, as suggested by conditioning theories of binge eating. A group of individuals with BN or BED (binge-eating group, n = 27) and a group of individuals with low trait food craving scores and without binge eating (control group, n = 19) reported their current food craving before and after a food cue exposure. Although food craving intensity significantly increased in both groups, this increase was significantly stronger in the binge-eating group than in the control group. This result is in line with conditioning models of binge eating that propose that food cues are conditioned stimuli that elicit a conditioned response (e.g., food craving) and that this association is stronger in individuals with binge eating. As food craving increased in individuals with low trait food craving scores as well—although to a lesser extent—previous null results might be explained by methodological considerations such as not screening control participants for trait food craving.

Reducing reward responsivity and daily food desires in female dieters through domain-specific training

ABSTRACTAccording to the strength model, self-regulation relies on a domain-general capacity that may be strengthened by training. From this perspective, training self-regulation in one domain may transfer to other domains. Here we used two inhibitory training paradigms, a domain-general and domain-specific stop-signal training task and compared their effects on brain reward activity as well as daily food desires in female dieters. Before and after the training, functional magnetic resonance imaging was used to assess food cue-reactivity, coupled with one week of smart-phone ecological momentary assessments to examine eating urges. Whereas the food-specific inhibitory training was successful in reducing both food cue-reactivity and food desires, the domain-general (sound-cue) training showed no transfer effects. These findings suggest that domain-specific training may be a more effective method for supporting self-regulation than domain-general approaches aimed at strengthening self-regulation across domains.

Neural processing of food cues in pre-pubertal children.

Neuroimaging investigations of brain pathways involved in reward and motivation have primarily focused on adults. This study sought to identify brain responses to visual food cues and explore its relationships with adiposity and sex in pre-pubertal children. Brain responses to palatable food vs. non-food cues were measured in 53 children (age: 8.18±.66years; sex: 22 boys, 31 girls) after an overnight fast. Whole-brain analysis (cluster-correction Z>2.3, P<.05) was performed to examine brain food cue reactivity and its relationships with adiposity and sex. Greater brain activity in response to food vs. non-food cues was observed in regions implicated in reward (orbital frontal cortex, striatum), taste (insula, postcentral gyrus), appetite (hypothalamus), emotion (amygdala), memory (hippocampus), visual processing (occipital cortex) and attention (parietal cortex). A negative association was found between percent body fat and food cue reactivity in the medial prefrontal cortex and lateral orbital frontal cortex adjusting for age and sex. Boys compared with girls had increased food cue reactivity in right hippocampus and visual cortex. These data suggest that body fat and sex are important moderators of brain food cue reactivity in children.

Food Cues and Obesity: Overpowering Hormones and Energy Balance Regulation.

In the modern obesogenic environment, food cues play a crucial role in the development of obesity by disrupting hormone and energy balance mechanisms. Thus, it is critical to understand the neurobiology of feeding behaviors and obesity in the context of ubiquitous food cues. The current paper reviews the physiology of feeding, hormonal regulation of energy balance, and food cue responses and discusses their contributions to obesity. Food cues have strong impact on human physiology. Obese individuals have altered food cue-elicited responses in the brain and periphery, overpowering hormone and energy balance regulation. Disrupted homeostasis during food cue exposure leads to continued food intake, unsuccessful weight management, and poor treatment outcomes, which further contributes to obesity epidemic. Findings from the review emphasize the crucial role of food cues in obesity epidemic, which necessitates multidimensional approaches to the prevention and treatment of obesity, including psychosocial interventions to reduce food cue reactivity, along with conventional treatment.

Do scores on the Food Craving Inventory and Three-Factor Eating Questionnaire correlate with expected brain regions of interest in people with obesity?

ObjectiveTo examine whether subscales of Food Craving Inventory (FCI) and Three-factor Eating Questionnaire (TFEQ) correlate with brain functional magnetic resonance imaging food-cue reactivity (fMRI-FCR) in the brain. MethodsThirty-two male and female adults with obesity (19–60years; 30–39.9kg/m2) participated in a 3-week dietary intervention (1120kcal/day from either 1) total meal replacement shakes, 2) portion-controlled typical food. FCI, TFEQ and fMRI-FCR were measured pre- and post-intervention. Correlations between pre-intervention fMRI-FCR and standardized pre-intervention FCI and TFEQ subscales; and also post- versus pre-intervention change in fMRI-FCR (ΔfMRI-FCR) and standardized changes in FCI and TFEQ subscales were examined at the whole brain level using tools in FMRIB Software Library. ResultsTwenty-eight subjects completed the intervention. Pre-intervention high-fat food cravings (P=0.041) and fast-food cravings (P=0.017) were negatively correlated with fMRI-FCR of several brain regions that regulate executive control over ingestion (i.e. bilateral lateral frontal pole, dorsolateral prefrontal cortex and dorsal anterior cingulate cortex). Post- vs. pre-intervention change in sweet (P=0.012) and fast food cravings (P=0.004) were negatively correlated with ΔfMRI-FCR of bilateral lateral frontal pole, dorsolateral prefrontal cortex, inferior frontal gyrus (pars opercularis) and dorsal anterior cingulate cortex (i.e. brain regions that regulate executive control over ingestion). Negative correlations were also observed between the changes in sweet and fast food cravings and ΔfMRI-FCR of brain regions that regulate food reward (i.e. bilateral mid-anterior insula, right nucleus accumbens), motor readiness to ingest (i.e. bilateral precentral gyrus), internally focused attention (i.e. bilateral precuneus and posterior cingulate cortex) and visual object recognition (i.e. occipital pole, lateral occipital cortex and middle and inferior temporal cortices). Changes in cravings for starchy food (P=0.032) and overall food cravings (P=0.027) were also negatively correlated with ΔfMRI-FCR of brain regions involved in regulating internally focused attention and visual object recognition. ConclusionsIn individuals with obesity, decreased food cravings seem to be reflective of increased fMRI-FCR of brain regions that regulate executive control over ingestion. Taken together, constructs measured by FCI seem to be reflective of neurophysiological processes underlying ingestive behavior and the changes in neurophysiological processes occurring during calorie restriction. Clinical trials registry numberNCT02637271; the protocol is available at https://clinicaltrials.gov/ct2/show/NCT02637271

Effects of Physical Activity and Sedentary Behavior on Brain Response to High-Calorie Food Cues in Young Adults.

BackgroundPhysical activity (PA) promotes weight maintenance, potentially due to its beneficial effects on feeding behavior regulation via diminished food cue reactivity within brain reward regions. We examined how levels of PA and sedentary behavior (SB) relate to brain responses to food cues.MethodsParticipants (22 lean, 18 obese) completed 3–5 PA recalls over 2 months. Average minutes/day of moderate to vigorous PA (MVPA) and SB were calculated. Participants completed a functional magnetic resonance imaging session, viewing food and non-food images following glucose ingestion. Region of interest (ROI) analysis examined associations between MVPA and brain percent signal change in response to food vs. non-food images, controlling for obesity and sex. Secondary analysis examined associations between SB and brain responses to food cues.ResultsGreater MVPA was associated with decreased food cue reactivity after glucose across brain ROIs (B=−0.00057, p=0.005), controlling for obesity and sex. Greater SB was associated with increased food cue reactivity after glucose across brain ROIs in unadjusted analyses (B=0.00041, p=0.026).ConclusionsPA may have beneficial effects on brain regulation of feeding behavior after caloric intake in lean individuals and individuals with obesity.

Effects of hunger state on the brain responses to food cues across the life span

The abundant exposure to food cues in our environment is one of the main drivers of overconsumption. Food evaluation is important for the regulation of food intake by the brain and it's interaction with hunger state. Children are especially susceptible to food cues. Understanding the mechanisms behind this regulation in healthy individuals across the life span can help to elucidate the mechanisms underlying overconsumption and aid the development of future obesity prevention strategies. Few functional neuroimaging studies have been done in children and elderly. Furthermore, it is unknown how hunger state affects neural food cue reactivity in these groups, since this has not been examined consistently.We examined the effects of hunger state and age on the brain responses to low- and high calorie foods. On two mornings, 122 participants (17 children; 38 teens; 36 adults; 31 elderly) performed a food image viewing task while being scanned using fMRI, either fasted or sated.Hunger induced greater activation during high versus low calorie food image viewing than satiety in the bilateral dorsomedial (dmPFC) and in the right dorsolateral prefrontal cortex (dlPFC) across all age groups. There was no significant main effect of age group on high versus low calorie food image viewing and no interaction between age group and hunger state.The greater activation of the dlPFC across all age groups during high calorie food image viewing in a fasted state might reflect increased inhibitory control in response to these foods. This may underlie the ability to resist overconsumption of high calorie foods. Furthermore, increased medial prefrontal cortex activation during hunger might reflect increased reward value of high calorie foods, which declines with satiation. Further studies are needed to better understand these results. Notably, overweight and obese individuals should be included to examine whether these responses are altered by weight status across the life span.

Influences of Dietary Added Sugar Consumption on Striatal Food-Cue Reactivity and Postprandial GLP-1 Response.

Sugar consumption in the United States exceeds recommendations from the American Heart Association. Overconsumption of sugar is linked to risk for obesity and metabolic disease. Animal studies suggest that high-sugar diets alter functions in brain regions associated with reward processing, including the dorsal and ventral striatum. Human neuroimaging studies have shown that these regions are responsive to food cues, and that the gut-derived satiety hormones, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY), suppress striatal food-cue responsivity. We aimed to determine the associations between dietary added sugar intake, striatal responsivity to food cues, and postprandial GLP-1 and PYY levels. Twenty-two lean volunteers underwent a functional magnetic resonance imaging (fMRI) scan during which they viewed pictures of food and non-food items after a 12-h fast. Before scanning, participants consumed a glucose drink. A subset of 19 participants underwent an additional fMRI session in which they consumed water as a control condition. Blood was sampled for GLP-1, and PYY levels and hunger ratings were assessed before and ~75 min after drink consumption. In-person 24-h dietary recalls were collected from each participant on three to six separate occasions over a 2-month period. Average percent calories from added sugar were calculated using information from 24-h dietary recalls. A region-of-interest analysis was performed to compare the blood oxygen level-dependent (BOLD) response to food vs. non-food cues in the bilateral dorsal striatum (caudate/putamen) and ventral striatum (nucleus accumbens). The relationships between added sugar, striatal responses, and hormone changes after drink consumption were assessed using Spearman’s correlations. We observed a positive correlation between added sugar intake and BOLD response to food cues in the dorsal striatum and a similar trend in the nucleus accumbens after glucose, but not water, consumption. Added sugar intake was negatively associated with GLP-1 response to glucose. Post hoc analysis revealed a negative correlation between GLP-1 response to glucose and BOLD response to food cues in the dorsal striatum. Our findings suggest that habitual added sugar intake is related to increased striatal response to food cues and decreased GLP-1 release following glucose intake, which could contribute to susceptibility to overeating.

Food product health warnings promote dietary self-control through reductions in neural signals indexing food cue reactivity.

Modern societies are replete with palatable food cues. A growing body of evidence suggests that food cue exposure activates conditioned appetitive physiological and psychological responses that may override current metabolic needs and existing eating goals, such as the desire to maintain a healthy diet. This conditioned response results in unhealthy dietary choices and is a contributing factor in the current obesity epidemic. Prime based obesity prevention measures such as health warnings at point-of-sale or on product packaging may have the potential to counteract the influence of the obesogenic environment at the crucial moment when people make food purchasing or consumption decisions. Existing research into the efficacy of these intervention strategies has predominantly employed self-report and population level measures, and little evidence exists to support the contention that these measures counteract food cue reactivity at the time of decision making. Using a dietary self-control priming paradigm, we demonstrated that brief exposure to food product health warnings enhanced dietary self-control. Further, we analysed electroencephalographic correlates of selective attention and food cue evoked craving (N1, P3, LPP) to show that health warning exposure reduced the automatic appetitive response towards palatable food cues. These findings contribute to existing evidence that exogenous information can successfully prime latent goals, and substantiate the notion that food product health warnings may provide a new avenue through which to curb excessive energy intake and reduce rising obesity rates.

Emotional ratings of high- and low-calorie food are differentially associated with cognitive restraint and dietary restriction

Dietary restraint is a robust risk factor for binge eating and eating disorders, which may partially result from increased reward reactivity to food in individuals who attempt to diet. However, research examining the association between dietary restraint and reactivity to food cues is mixed. Mixed findings may reflect distinct relations between food cue reactivity and different dimensions of dietary behavior; attempts to diet (cognitive restraint) may be associated with increased positive evaluations of food, whereas actual reduction in food intake (dietary restriction) may be achieved through decreased reactivity to food cues. The aim of the current study was to examine whether cognitive restraint and dietary restriction, as assessed via subscales on a recently developed multidimensional measure of eating pathology (i.e., Eating Pathology Symptoms Inventory [EPSI]), are differentially associated with emotional evaluations of high- and low-calorie food. Female participants (N = 203) viewed 12 high-calorie (i.e., sweet, savory) and 12 low-calorie (i.e., fruits, vegetables) food images, as well as 36 standard emotional images. Images were rated on the dimensions of valence, arousal, and craving using the Self-Assessment Manikin. Cognitive restraint was correlated with greater pleasure and craving ratings of low-calorie, but not high-calorie, foods. In contrast, dietary restriction was related to reduced pleasure and craving ratings for both high- and low-calorie foods. Findings suggest that cognitive restraint may be associated with a preference for low-calorie foods; whereas dietary restriction may relate to reduced sensitivity to the hedonic and motivational value of food, regardless of caloric content. Results also provide support for the distinction between cognitive restraint and dietary restriction, as assessed via the EPSI.

Is hunger important to model in fMRI visual food-cue reactivity paradigms in adults with obesity and how should this be done?

We considered 1) influence of self-reported hunger in behavioral and fMRI food-cue reactivity (fMRI-FCR) 2) optimal methods to model this.Adults (N = 32; 19–60 years; F = 21; BMI 30–39.9 kg/m2) participated in an fMRI-FCR task that required rating 240 images of food and matched objects for ‘appeal’. Hunger, satiety, thirst, fullness and emptiness were measured pre- and post-scan (visual analogue scales). Hunger, satiety, fullness and emptiness were combined to form a latent factor (appetite). Post-vs. pre-scores were compared using paired t-tests. In mixed-effects models, appeal/fMRI-FCR responses were regressed on image (i.e. food/objects), with random intercepts and slopes of image for functional runs nested within subjects. Each of hunger, satiety, thirst, fullness, emptiness and appetite were added as covariates in 4 forms (separate models): 1) change; 2) post- and pre-mean; 3) pre-; 4) change and pre-.Satiety decreased (Δ = −13.39, p = 0.001) and thirst increased (Δ = 11.78, p = 0.006) during the scan. Changes in other constructs were not significant (p’s > 0.05). Including covariates did not influence food vs. object contrast of appeal ratings/fMRI-FCR. Significant image X covariate interactions were observed in some fMRI models. However, including these constructs did not improve the overall model fit.While some subjective, self-reported hunger, satiety and related constructs may be moderating fMRI-FCR, these constructs do not appear to be salient influences on appeal/fMRI-FCR in people with obesity undergoing fMRI.

Effects of 3-week total meal replacement vs. typical food-based diet on human brain functional magnetic resonance imaging food-cue reactivity and functional connectivity in people with obesity

ObjectivesCalorie restriction via total meal replacement (TMR) results in greater reduction of food cravings compared to reduced-calorie typical diet (TD). Direct evidence of the impact of these interventions on human brain fMRI food-cue reactivity (fMRI-FCR) and functional connectivity is absent. We examined the effects of a 3-week 1120 kcal/d TMR intervention as compared to an iso-caloric TD intervention using an fMRI-FCR paradigm. MethodsThirty-two male and female subjects with obesity (19–60 years; 30–39.9 kg/m2) participated in a randomized two-group repeated measures dietary intervention study consisting of 1120 kcal/d from either 1) TMR (shakes), 2) TD (portion control). Pre-intervention and following the 3-week diet fMRI-FCR, functional connectivity, food cravings (Food Craving Inventory) and weight were considered. ResultsCompared to TD, TMR showed increased fMRI-FCR of the bilateral dorsolateral prefrontal (dlPFC), orbitofrontal, anterior cingulate, primary motor and left insular cortices and bilateral nucleus accumbens regions in the post-intervention state relative to the pre-intervention state. Compared to TD, TMR was also associated with negative modulation of fMRI-FCR of the nucleus accumbens, orbitofrontal cortex and amygdala by dlPFC. Reduced body weight (4.87 kg, P < 0.001), body fat (2.19 kg, P = 0.004) and overall food cravings (0.41, P = 0.047) were seen in the TMR group. In the TD group reduced body weight (2.37 kg, P = 0.004) and body fat (1.64 kg, P = 0.002) were noted. Weight loss was significantly greater in TMR versus TD (2.50 kg, P = 0.007). ConclusionsGreater weight loss and reduced cravings, coupled with stronger activations and potential negative modulation of the food reward related regions by the dlPFC during exposure to visual food cues is consistent with increased executive control in TMR vs. TD.

Cue exposure therapy reduces overeating of exposed and non-exposed foods in obese adolescents

Background and objectivesThis study tested whether two sessions of food cue exposure therapy reduced eating in the absence of hunger (EAH), specified for exposed and non-exposed food, in overweight and obese adolescents, and whether habituation of food cue reactivity and reduced CS-US expectancies predicted a decrease in EAH. Methods41 overweight adolescents (aged 12–18 years) were randomly assigned to a cue exposure intervention or a lifestyle intervention (control condition). Habituation of food cue reactivity (self-reported desire to eat and salivation) and CS-US expectancy were measured during both sessions, and EAH was measured at the end of session two. ResultsCompared to the control condition, the cue exposure condition showed less EAH for the exposed food item as well as for the non-exposed food items. Larger within-session (WSH) and between-session habituation (BSH) of cue reactivity were not related to less EAH, change in CS-US expectancy was unrelated to EAH. LimitationsThe study was underpowered, and compliance to homework instructions between sessions was poor, intervention effects might have been larger when participants adhered to daily homework exercises. ConclusionsFood cue exposure was effective to reduce EAH of exposed and non-exposed food items, indicating generalisability of the exposure effect. In line with exposure effects in anxiety disorders, habituation was not found to benefit outcome, though the present data do also not provide evidence that CS-US expectancy violation predicts EAH.