Food or money? Children's brains respond differently to rewards regardless of weight status

Loss of control eating in children is associated with altered cortical and subcortical brain structure

Introduction

Loss of control (LOC) eating is the perceived inability to control how much is eaten, regardless of actual amount consumed. Childhood LOC-eating is a risk factor for the development of binge-eating disorder (BED), but its neurobiological basis is poorly understood. Studies in children with BED have shown both increased gray matter volume in regions related to top-down cognitive control (e.g., dorsolateral prefrontal cortex) and reward-related decision making (e.g., orbital frontal cortex) relative to healthy controls. However, no studies have examined brain structure in children with LOC-eating. To identify potential neurobiological precursors of BED, we conducted secondary analysis of five studies that conducted T1 MPRAGE scans.

Methods

A total of 143, 7-12-year-old children (M = 8.9 years, 70 boys) were included in the study, 26% of which (n = 37) reported LOC-eating (semi-structured interview). Age, sex, and obesity status did not differ by LOC-eating. Differences between children with and without LOC were examined for gray matter volume, cortical thickness, gyrification, sulci depth, and cortical complexity after adjusting for age, sex, total intercranial volume, weight status, and study.

Results

Children with LOC, relative to those without, had greater gray matter volume in right orbital frontal cortex but lower gray matter volume in right parahippocampal gyrus, left CA4/dentate gyrus, and left cerebellar lobule VI. While there were no differences in cortical thickness or gyrification, children with LOC-eating had great sulci depth in left anterior cingulate cortex and cuneus and greater cortical complexity in right insular cortex.

Discussion

Together, this indicates that children with LOC-eating have structural differences in regions related to cognitive control, reward-related decision-making, and regulation of eating behaviors.

Neural correlates of appetite in adolescents

Appetitive characteristics are associated with child adiposity, but their biological underpinnings are unclear. We sought to investigate the neural correlates of psychometric and behavioral measures of appetitive characteristics in youth. Adolescents (14-18y; 39F, 37M) varying in familial obesity risk and body weight (20% with overweight, 24% with obesity) viewed pictures of high energy-density (ED) foods, low-ED foods and non-foods during fMRI scanning on two separate days. On one day participants consumed a 474 ml preload of water (0 kcal, fasted) and on another (counter-balanced) 474 ml milkshake (480 kcal, fed), before scanning. A multi-item ad libitum meal (ALM) followed scanning. Parents completed Child Eating Behavior Questionnaire (CEBQ) sub-scales assessing food approach and food self-regulation. Caloric compensation was calculated as the percentage of preload intake compensated for by down-regulation of ALM intake in the fed vs. fasted condition. Analyses correcting for multiple comparisons demonstrated that, for the fasted condition, higher CEBQ Food Responsiveness scores were associated with greater activation to high-ED (vs. low-ED) foods in regions implicated in food reward (insula, rolandic operculum, putamen). In addition, higher caloric compensation was associated with greater fed vs. fasted activations in response to foods (vs. non-foods) in thalamus and supramarginal gyrus. Uncorrected analyses provided further support for associations of different measures of appetitive characteristics with brain responses to food cues in each condition. Measures of appetitive characteristics demonstrated overlapping and distinct associations with patterns of brain activation elicited by food cues in fasted and fed states. Understanding the neural basis of appetitive characteristics could aid development of biobehaviorally-informed obesity interventions.

Switching between foods: A potential behavioral phenotype of hedonic hunger and increased obesity risk in children

CONTEXT

Reward-based eating is a trait that increases risk for eating in the absence of hunger (EAH) and obesity. Eating behaviors such as switching more frequently between different foods may increase intake during EAH by delaying the onset of sensory-specific satiation (SSS); however, this question has not been empirically tested.

OBJECTIVES

1) Test whether switching between foods mediates the relationship between reward-based eating and EAH intake. 2) Test whether switching between foods during EAH moderates the relationship between reward-based eating and weight status.

METHODS

Data were analyzed from a study assessing decision-making in children (n = 63 children; 9.4 ± 1.4 years, 77.0 ± 22.4 BMI%tile). Reward-based eating was quantified using the Children's Eating Behaviour Questionnaire. EAH was assessed as the amount of palatable food consumed following ad libitum consumption of a standard meal. Videos of eating behavior were coded for eating time, number of different foods consumed, and food switches. Ordinary least squares regressions were conducted to test hypotheses.

RESULTS

Switching was positively associated with EAH intake for both kcal (p < 0.01) and grams (p < 0.01) such that each additional switch was associated with an increased intake of 17.0 kcal or 3.5 gs. Switching mediated the relationship between reward-based eating and EAH (p < 0.01) such that more frequent switching fully accounted for the positive association between reward-based eating and EAH (ps < 0.01). While reward-based eating was also positively associated with weight status (p < 0.01), this association was moderated by food switching (p < 0.01) such that the relationship was stronger for children who switch more frequently (p < 0.01).

CONCLUSIONS

Frequent switching between foods was positively associated with EAH intake and mediated the relationship between reward-based eating and EAH. Moreover, reward-based eating was more strongly related to weight status in children who switched more frequently. Thus, food switching may contribute to overconsumption and be an important behavioral indicator of increased obesity risk in children. Studies across multiple meals and contexts will help determine if switching is a reliable behavioral phenotype.

Attributes of parenting identities and food practices among parents in Nairobi, Kenya

Dramatic changes in daily life are leading to increased rates of obesity and non-communicable diseases (NCD) in Kenya, including among children. Parenting plays a vital role in helping children establish healthy eating habits to prevent obesity and NCDs. The objective of this study was to describe parenting identity and how attributes of parenting influence food parenting practices in an urban Kenyan context. A qualitative study design was employed with 18 participants recruited using quota sampling to include parents who were born in (n = 8) or migrated to Nairobi in the last five years (n = 10). In-depth qualitative interviews were conducted by an experienced ethnographic interviewer that inquired about parenting identity and food parenting practices. Transcripts were analyzed using thematic coding in a multi-step and emergent process. Parents described their parenting identities as an integration of tradition and personal experiences during their upbringing with the modern realities of daily life. Their own experiences with discipline, modern urban lifestyles, and social pressures were dominant influences on their identities. Parenting identities included four distinct but related attributes: good disciplinarian, trustworthy, protective, and balanced provider and nurturer. Food parenting practices were described as expressions of parenting identity and included the goals: children becoming better eaters; nourishing through food; impart joy; and bonding. The study findings illustrate the influence of modern urban lifestyles on food parenting identities and practices. Understanding emerging identities and practices in rapidly changing low- and middle-income countries (LMIC) contexts is essential for health promoting policies and programs.

Gray matter volume and functional connectivity underlying binge eating in healthy children

PURPOSE

As a maladaptive disordered eating behavior, binge eating (BE) onset has been reported in children as young as eight years old and is linked with a range of negative psychological consequences. However, previous neuroimaging research of BE has mainly focused on adults in clinical conditions, and little is known about the potential neurostructural and neurofunctional bases of BE in healthy children.

METHODS

In this study, we examined these issues in 76 primary school students (mean age = 9.86 years) using voxel-based morphometry and resting-state functional connectivity (rsFC) approaches.

RESULTS

After controlling for age, sex, and total intracranial volume/head motion, we observed that higher levels of BE were correlated with greater gray matter volumes (GMV) in the left fusiform and right insula and weaker rsFC between the right insula and following three regions: right orbital frontal cortex, left cingulate gyrus, and left superior frontal gyrus. No significant associations were observed between BE and regional white matter volume. Significant sex differences were found only in the relationship between BE and GMV in the left fusiform. Furthermore, the GMV- and rsFC-based predictive models (a machine-learning method) achieved significant correlations between the actual and predicted BE values, demonstrating the robustness of our findings.

CONCLUSION

The present study provides novel evidence for the brain structural and functional substrates of children's BE, and further reveals that the weakened communication between core regions associated with negative affectivity, reward responsivity, and executive function is strongly related to dysregulated eating.

LEVEL OF EVIDENCE

Level V, descriptive study.

Heterogeneity in PFC-amygdala connectivity in middle childhood, and concurrent interrelations with inhibitory control and anxiety symptoms

The prefrontal cortex (PFC) is a key brain area in considering adaptive regulatory behaviors. This includes regulatory projections to regions of the limbic system such as the amygdala, where the nature of functional connections may confer lower risk for anxiety disorders. The PFC is also associated with behaviors like executive functioning. Inhibitory control is a behavior encompassed by executive functioning and is generally viewed favorably for adaptive socioemotional development. Yet, some research suggests that high levels of inhibitory control may actually be a risk factor for some maladaptive developmental outcomes, like anxiety disorders. In a sample of 51 children ranging from 7 to 9 years old, we examined resting state functional connectivity between regions of the PFC and the amygdala. We used Subgrouping Group Iterative Multiple Model Estimation (S-GIMME) to identify and characterize data-driven subgroups of individuals with similar networks of connectivity between these brain regions. Generated subgroups were collapsed into children characterized by the presence or absence of recovered connections between the PFC and amygdala. For subsets of children with available data (N = 38-44), we then tested whether inhibitory control, as measured by a stop signal task, moderated the relation between these subgroups and child-reported anxiety symptoms. We found an inverse relation between stop-signal reaction times and reported count of anxiety symptoms when covarying for connectivity group, suggesting that greater inhibitory control was actually related to greater anxiety symptoms, but only when accounting for patterns of PFC-amygdala connectivity. These data suggest that there is a great deal of heterogeneity in the nature of functional connections between the PFC and amygdala during this stage of development. The findings also provide support for the notion of high levels of inhibitory control as a risk factor for anxiety, but trait-level biopsychosocial factors may be important to consider in assessing the nature of risk.

Influence of exclusive breastfeeding on hippocampal structure, satiety responsiveness, and weight status

Longer exclusive breastfeeding duration has been associated with differences in neural development, better satiety responsiveness, and decreased risk for childhood obesity. Given hippocampus sensitivity to diet and potential role in the integration of satiety signals, hippocampus may play a role in these relationships. We conducted a secondary analysis of 149, 7–11‐year‐olds (73 males) who participated in one of five studies that assessed neural responses to food cues. Hippocampal grey matter volume was extracted from structural scans using CAT12, weight status was assessed using age‐ and sex‐adjusted body mass index (%BMI_p85), and parents reported exclusive breastfeeding duration and satiety responsiveness (Children's Eating Behaviour Questionnaire). Separate path models for left and right hippocampus tested: (1) the direct effect of exclusive breastfeeding on satiety responsiveness and its indirect effect through hippocampal grey matter volume; (2) the direct effect of hippocampal grey matter volume on %BMI_p85 and its indirect effect through satiety responsiveness. %BMI_p85 was adjusted for maternal education, yearly income, and premature birth while hippocampal grey matter volume was adjusted for total intercranial volume, age, and study from which data were extracted. Longer exclusive breastfeeding duration was associated with greater bilateral hippocampal grey matter volumes. In addition, better satiety responsiveness and greater left hippocampal grey matter volume were both associated with lower %BMI_p85. However, hippocampal grey matter volumes were not associated with satiety responsiveness. Although no relationship was found between breastfeeding and child weight status, these results highlight the potential impact of exclusive breastfeeding duration on the hippocampal structure.

Longer exclusive breastfeeding was associated with greater bilateral hippocampal grey matter volume but not satiety responsiveness in children.

While exclusive breastfeeding duration was not directly associated with weight status, better satiety responsiveness and greater left hippocampal grey matter volume were both associated with lower weight status in children.

This study highlights the potential impact of exclusive breastfeeding on hippocampal structure, providing a possible mechanism in which breastfeeding may reduce the risk for excess childhood weight gain.

Future studies need to determine the relative impact that complementary periods of breastfeeding may have on regional brain development and satiety responsiveness.

Decision-Making Processes Related to Perseveration Are Indirectly Associated With Weight Status in Children Through Laboratory-Assessed Energy Intake

Decision-making contributes to what and how much we consume, and deficits in decision-making have been associated with increased weight status in children. Nevertheless, the relationships between cognitive and affective processes underlying decision-making (i.e., decision-making processes) and laboratory food intake are unclear. We used data from a four-session, within-subjects laboratory study to investigate the relationships between decision-making processes, food intake, and weight status in 70 children 7-to-11-years-old. Decision-making was assessed with the Hungry Donkey Task (HDT), a child-friendly task where children make selections with unknown reward outcomes. Food intake was measured with three paradigms: (1) a standard ad libitum meal, (2) an eating in the absence of hunger (EAH) protocol, and (3) a palatable buffet meal. Individual differences related to decision-making processes during the HDT were quantified with a reinforcement learning model. Path analyses were used to test whether decision-making processes that contribute to children’s (a) expected value of a choice and (b) tendency to perseverate (i.e., repeatedly make the same choice) were indirectly associated with weight status through their effects on intake (kcal). Results revealed that increases in the tendency to perseverate after a gain outcome were positively associated with intake at all three paradigms and indirectly associated with higher weight status through intake at both the standard and buffet meals. Increases in the tendency to perseverate after a loss outcome were positively associated with EAH, but only in children whose tendency to perseverate persistedacross trials. Results suggest that decision-making processes that shape children’s tendencies to repeat a behavior (i.e., perseverate) are related to laboratory energy intake across multiple eating paradigms. Children who are more likely to repeat a choice after a positive outcome have a tendency to eat more at laboratory meals. If this generalizes to contexts outside the laboratory, these children may be susceptible to obesity. By using a reinforcement learning model not previously applied to the study of eating behaviors, this study elucidated potential determinants of excess energy intake in children, which may be useful for the development of childhood obesity interventions.

Children's inhibitory control abilities in the presence of rewards are related to weight status and eating in the absence of hunger

The Reflective-Impulsive Dual Processes Model suggests that overeating occurs when the temptation to consume food overrides inhibitory control processes. However, how rewards interact with inhibitory control and their relation to children's weight status and food intake is not understood. Here, 7-to-11-year-old children (n = 66; 32 overweight/obese) completed two versions (baseline [i.e., non-reward incentivized/control] and reward incentivized [food, money, no reward]) of a Go/Nogo task. Intake of palatable foods in the absence of hunger (i.e., eating in the absence of hunger-EAH) was measured following a standardized meal. A drift diffusion model was used to characterize children's performance parameters on the Go/Nogo. On the baseline Go/Nogo, children with higher weight status responded more cautiously, but on reward trials for food/money children were more cautions and made more false alarms relative to the no reward condition. Energy intake during EAH positively correlated with FA errors for food and money vs. no reward, but sex moderated this effect such that FA positively associated with EAH in girls but not boys. Independent of sex, FA for money vs. no reward and food vs. money were both positively associated with energy consumed during EAH. These results suggest that the presence of food and money rewards impair inhibitory control processing, especially in children with higher weight status. Further, increased inhibitory control impairment in response to food rewards, specifically, may be a risk factor for disinhibited eating in girls. Though preliminary, results may be useful in the development of targeted treatments to help moderate excess consumption in children.

Evaluation of a child food reward task and its association with maternal feeding practices

Food reward is defined as the momentary value of a food to the individual at the time of ingestion and is characterised by two psychological processes-"liking" and "wanting". We aimed to validate an age-appropriate food reward task to quantify implicit wanting of children from the GUSTO cohort (n = 430). At age 5 years, child appetitive traits and maternal feeding practices were reported by mothers via questionnaires. At age 6, a write-for-food task based on the child's preference for food or toy rewards was undertaken in laboratory conditions. Child BMI and skinfold measurements were taken at age 7. Convergent validity of the food reward task was assessed by associating with child appetitive traits, where enjoyment of food/food responsiveness (OR: 1.51; 95% CI: 1.06, 2.15) and emotional overeating (OR: 1.64; 95% CI: 1.09, 2.48) were positively associated with high food reward in children. Criterion validity was tested by associating with child BMI, however no significant relationships were observed. Multivariable logistic regression analysis with maternal feeding practices revealed that children whose mother tend to restrict unhealthy food (OR: 1.37; 95% CI: 1.03, 1.82) and girls whose mothers taught them about nutrition (OR: 2.09; 95% CI: 1.19, 3.67) were more likely to have high food reward. No further significant associations were observed between food reward, other appetitive traits and feeding practices. Despite the lack of association with child weight status, this study demonstrated the value of the write-for-food task to assess food reward in children and presented sex-specific associations with maternal feeding practices.

Multimodal brain predictors of current weight and weight gain in children enrolled in the ABCD study ®

Multimodal neuroimaging assessments were utilized to identify generalizable brain correlates of current body mass index (BMI) and predictors of pathological weight gain (i.e., beyond normative development) one year later. Multimodal data from children enrolled in the Adolescent Brain Cognitive Development Study® at 9-to-10-years-old, consisted of structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), resting state (rs), and three task-based functional (f) MRI scans assessing reward processing, inhibitory control, and working memory. Cross-validated elastic-net regression revealed widespread structural associations with BMI (e.g., cortical thickness, surface area, subcortical volume, and DTI), which explained 35% of the variance in the training set and generalized well to the test set (R2 = 0.27). Widespread rsfMRI inter- and intra-network correlations were related to BMI (R2train = 0.21; R2test = 0.14), as were regional activations on the working memory task (R2train = 0.20; (R2test = 0.16). However, reward and inhibitory control tasks were unrelated to BMI. Further, pathological weight gain was predicted by structural features (Area Under the Curve (AUC)train = 0.83; AUCtest = 0.83, p < 0.001), but not by fMRI nor rsfMRI. These results establish generalizable brain correlates of current weight and future pathological weight gain. These results also suggest that sMRI may have particular value for identifying children at risk for pathological weight gain.

Individual differences in the influence of taste and health impact successful dietary self-control: A mouse tracking food choice study in children

In order to improve dietary quality among children, there is a need to understand how they make decisions about what foods to eat. This study used a mouse tracking food choice task to better understand how attributes such as health and taste contribute to food decisions among 70 children aged 7-to-11 years old. Children rated health, taste, and desire to eat for 76 common foods that varied in energy density and then used a computer mouse to select which of two presented foods they would like to eat. The presented food pairs were based on children's own ratings of taste and health so that some trials required self-control to choose the healthier option (i.e., healthy/not tasty paired with unhealthy/tasty). Children's body mass index (BMI) percentile was not associated with number of healthy choices. To examine mouse trajectories, we replicated previous analytic techniques and applied a novel technique, time-varying effects modeling (TVEM). Results showed that desire to eat impacted food decision-making sooner than taste and health during trials that required self-control, with TVEM showing that early discounting of desire to eat enabled healthier choices. However, these temporal dynamics varied by age, BMI percentile, and overall self-control performance in the task. When the less healthy food was chosen (i.e., self-control failure), older children and children with better overall self-control were more influenced by taste and desire to eat. However, children with higher BMI percentiles showed stronger discounting (i.e., negative influence) of taste when choosing the healthier food. Together this highlights how the influence of hedonic food attributes on food decision-making varies by individual child-level characteristics. Understanding individual differences in the cognitive processes that support healthy food choices in children may help identify targets for interventions aimed at improving child nutrition.

Is obesity related to enhanced neural reactivity to visual food cues? A review and meta-analysis

Theoretical work suggests that obesity is related to enhanced incentive salience of food cues. However, evidence from both behavioral and neuroimaging studies on the topic is mixed. In this work we review the literature on cue reactivity in obesity and perform a preregistered meta-analysis of studies investigating effects of obesity on brain responses to passive food pictures viewing. Further, we examine whether age influences brain responses to food cues in obesity. In the meta-analysis we included 13 studies of children and adults that investigated group differences (obese vs. lean) in responses to food vs. non-food pictures viewing. While we found no significant differences in the overall meta-analysis, we show that age significantly influences brain response differences to food cues in the left insula and the left fusiform gyrus. In the left insula, obese vs. lean brain differences in response to food cues decreased with age, while in the left fusiform gyrus the pattern was opposite. Our results suggest that there is little evidence for obesity-related differences in responses to food cues and that such differences might be mediated by additional factors that are often not considered.

"Food" and "non-food" self-regulation in childhood: a review and reciprocal analysis

BACKGROUND

In developmental science, there is an extensive literature on non-food related self-regulation in childhood, where several domains relating to emotions, actions and cognitions have been identified. There is now growing attention to food related self-regulation in childhood, especially difficulties with ASR, and the consequences for weight gain and adiposity. The aim of this narrative review was to conduct a reciprocal analysis of self-regulation in the food and non-food domains in childhood (referred to as appetite self-regulation (ASR) and general self-regulation (GSR) respectively). The focus was on commonalities and differences in key concepts and underpinning processes.

METHODS

Databases and major journals were searched using terms such as self-regulation, appetite self-regulation, or self-regulation of energy intake, together with associated constructs (e.g., Executive Function, Effortful Control, delay-of-gratification). This was followed by backward and forward snowballing.

RESULTS AND DISCUSSION

The scholarship on GSR in childhood has had a focus on the role of the cognitively-oriented Executive Function (EF), the temperamentally-based Effortful Control (EC) and the recursive interplay between bottom-up (reactive, emotion driven, approach or avoidance) and top-down (cognitive, conscious decision-making) processes. "Hot" and "cool/cold" EF and self-regulation situations have been distinguished. There were some parallels between GSR and ASR in these areas, but uncertainty about the contribution of EF and EC to ASR in young children. Possible differences between the contribution to ASR-related outcomes of delay-of-gratification in food and non-food tasks were apparent. Unique elements of ASR were identified; associated with psychological, biological and neurological responses to food and bottom-up processes. A diverse number of situations or elements connected to ASR exist: for example, energy balance homeostasis, caloric compensation, hunger regulation, satiation, satiety, energy density of food, eating in the absence of hunger, emotional eating, etc. CONCLUSIONS: Self-regulation in food and non-food domains are amenable to a reciprocal analysis. We argue that self-regulation of appetite should be added as a domain under the umbrella of self-regulation in childhood along with the other non-food related domains. This could lead to a broader understanding of self-regulation in childhood, and generate novel lines of enquiry.

Is brain response to food rewards related to overeating? A test of the reward surfeit model of overeating in children

The reward surfeit model of overeating suggests that heightened brain response to rewards contributes to overeating and subsequent weight gain. However, previous studies have not tested whether brain response to reward is associated with food intake, particularly during childhood, a period of dynamic development in reward and inhibitory control neurocircuitry. We conducted functional magnetic resonance imaging (fMRI) with 7-11-year-old children (n = 59; healthy weight, n = 31; overweight, n = 28; 54% female) while they played a modified card-guessing paradigm to examine blood-oxygen-level-dependent (BOLD) response to anticipating and winning rewards (food, money, neutral). Food intake was assessed at three separate meals that measured different facets of eating behavior: 1) typical consumption (baseline), 2) overindulgence (palatable buffet), and 3) eating in the absence of hunger (EAH). A priori regions of interest included regions implicated in both reward processing and inhibitory control. Multiple stepwise regressions were conducted to examine the relationship between intake and BOLD response to rewards. Corrected results showed that a greater BOLD response in the medial prefrontal cortex for anticipating food compared to money positively correlated with how much children ate at the baseline and palatable buffet meals. BOLD response in the dorsolateral prefrontal cortex for winning food compared to money was positively correlated with intake at the palatable buffet meal and EAH. All aforementioned relationships were independent of child weight status. Findings support the reward surfeit model by showing that increased brain response to food compared to money rewards positively correlates with laboratory measures of food intake in children.