Calorie Labeling Promotes Dietary Self-Control by Shifting the Temporal Dynamics of Health- and Taste-Attribute Integration in Overweight Individuals

Understanding why people make unhealthy food choices and how to promote healthier choices is critical to prevent obesity. Unhealthy food choices may occur when individuals fail to consider health attributes as quickly as taste attributes in their decisions, and this bias may be modifiable by health-related external cues. One hundred seventy-eight participants performed a mouse-tracking food-choice task with and without calorie information. With the addition of calorie information, participants made healthier choices. Without calorie information, the initial integration of health attributes in overweight individuals’ decisions was about 230 ms delayed relative to the taste attributes, but calorie labeling promoted healthier choices by speeding up the integration of health attributes during a food-choice task. Our study suggests that obesogenic choices are related to the relative speed with which taste and health attributes are integrated into the decision process and that this bias is modifiable by external health-related cues.

On how patients with multiple sclerosis weigh side effect severity and treatment efficacy when making treatment decisions

Although effective disease-modifying treatments (DMTs) are available for individuals suffering from multiple sclerosis (MS), many patients fail to take their recommended medications. Unlike medications that provide immediate relief from existing symptoms, DMTs decrease the probability of future symptoms (i.e., a probabilistic benefit) while concurrently carrying an appreciable risk of immediate side effects (i.e., a probabilistic cost). Prior research has shown that both the probability of reducing disease progression and the probability of experiencing side effects impact patients' likelihood of taking a hypothetical DMT. The role that side effect severity plays in treatment decisions remains unexplored. The present study examined how probability of medication efficacy and side effect severity impact patients' likelihood of taking hypothetical DMTs. Patients' likelihood of taking a DMT systematically decreased as medication efficacy decreased and side effect severity increased. Because side effect severity appears to impact decision-making processes in unique ways, the present results suggest that providers should present information on severe (which are typically rare) and mild to moderate side effects (which are more common) separately. (PsycINFO Database Record

Using EP50 to forecast treatment adherence in individuals with multiple sclerosis

Much like delay discounting, probability discounting may be related to a host of pro-health behaviors. In a recent report, a Medical Decision Making Questionnaire (MDMQ) was developed that leveraged this insights of probability discounting to both describe ways that multiple sclerosis (MS) patients weigh costs and benefits when making adherence choices, and predicted their self-reported treatment adherence. The current re-analysis of those data use a novel EP50 measure as a framework of a model that predicted the cost/benefit ratios necessary for the choices of typically non-adherent patients to become indistinguishable from those of typically adherent patients (and vice versa). These analytic tools may aid in the development/evaluation of both novel therapeutics and treatment adherence strategies for chronic conditions.

The child brain computes and utilizes internalized maternal choices

As children grow, they gradually learn how to make decisions independently. However, decisions like choosing healthy but less-tasty foods can be challenging for children whose self-regulation and executive cognitive functions are still maturing. We propose a computational decision-making process in which children estimate their mother's choices for them as well as their individual food preferences. By employing functional magnetic resonance imaging during real food choices, we find that the ventromedial prefrontal cortex (vmPFC) encodes children's own preferences and the left dorsolateral prefrontal cortex (dlPFC) encodes the projected mom's choices for them at the time of children's choice. Also, the left dlPFC region shows an inhibitory functional connectivity with the vmPFC at the time of children's own choice. Our study suggests that in part, children utilize their perceived caregiver's choices when making choices for themselves, which may serve as an external regulator of decision-making, leading to optimal healthy decisions.

Mothers advocate eating healthy foods while children like to eat tasty foods. Lim and colleagues demonstrate that children incorporate their mothers' food choices while deciding what to eat as well as provide the neural correlates of this decision making process.

Resting-state brain connectivity after surgical and behavioral weight loss

OBJECTIVE

Changes in food-cue neural reactivity associated with behavioral and surgical weight loss interventions have been reported. Resting functional connectivity represents tonic neural activity that may contribute to weight loss success. This study explores whether intervention type is associated with differences in functional connectivity after weight loss.

METHODS

Fifteen participants with obesity were recruited prior to adjustable gastric banding surgery. Thirteen demographically matched participants with obesity were selected from a separate behavioral diet intervention. Resting-state functional magnetic resonance imaging was collected 3 months after surgery/behavioral intervention. ANOVA was used to examine post-weight loss differences between the two groups in connectivity to seed regions previously identified as showing differential cue-reactivity after weight loss.

RESULTS

Following weight loss, behavioral dieters exhibited increased connectivity between left precuneus/superior parietal lobule (SPL) and bilateral insula pre- to postmeal and bariatric patients exhibited decreased connectivity between these regions pre- to postmeal (P(corrected) <0.05).

CONCLUSIONS

Behavioral dieters showed increased connectivity pre- to postmeal between a region associated with processing of self-referent information (precuneus/SPL) and a region associated with interoception (insula) whereas bariatric patients showed decreased connectivity between these regions. This may reflect increased attention to hunger signals following surgical procedures and increased attention to satiety signals following behavioral diet interventions.

Can neural activation in dorsolateral prefrontal cortex predict responsiveness to information? An application to egg production systems and campaign advertising

Consumers prefer to pay low prices and increase animal welfare; however consumers are typically forced to make tradeoffs between price and animal welfare. Campaign advertising (i.e., advertising used during the 2008 vote on Proposition 2 in California) may affect how consumers make tradeoffs between price and animal welfare. Neuroimaging data was used to determine the effects of brain activation in dorsolateral prefrontal cortex (dlPFC) on choices making a tradeoff between price and animal welfare and responsiveness to campaign advertising. Results indicated that activation in the dlPFC was greater when making choices that forced a tradeoff between price and animal welfare, compared to choices that varied only by price or animal welfare. Furthermore, greater activation differences in right dlPFC between choices that forced a tradeoff and choices that did not, indicated greater responsiveness to campaign advertising.

Prospect theory and body mass: characterizing psychological parameters for weight-related risk attitudes and weight-gain aversion

We developed a novel decision-making paradigm that allows us to apply prospect theory in behavioral economics to body mass. 67 healthy young adults completed self-report measures and two decision-making tasks for weight-loss, as well as for monetary rewards. We estimated risk-related preference and loss aversion parameters for each individual, separately for weight-loss and monetary rewards choice data. Risk-seeking tendency for weight-loss was positively correlated with body mass index in individuals who desired to lose body weight, whereas the risk-seeking for momentary rewards was not. Risk-seeking for weight-loss was correlated to excessive body shape preoccupations, while aversion to weight-gain was correlated with self-reports of behavioral involvement for successful weight-loss. We demonstrated that prospect theory can be useful in explaining the decision-making process related to body mass. Applying prospect theory is expected to advance our understanding of decision-making mechanisms in obesity, which might prove helpful for improving healthy choices.

Can't wait to lose weight? Characterizing temporal discounting parameters for weight-loss

Obesity is often related to steeper temporal discounting, that is, higher decision impulsivity for immediate rewards over delayed rewards. However, previous studies have measured temporal discounting parameters through monetary rewards. The aim of this study was to develop a temporal discounting measure based on weight-loss rewards, which may help to understand decision-making mechanisms more closely related to body weight regulation. After having their heights and weights measured, healthy young adults completed the Monetary Choice Questionnaire (MCQ), and an adapted version of the MCQ, with weight-loss as a reward. Participants also completed self-reports that measure obesity-related cognitive variables. For 42 participants who expressed a desire to lose weight, weight-loss rewards were discounted over time and had a positive correlation with temporal discounting for monetary rewards. Higher temporal discounting for weight loss rewards (i.e., preference for immediate weight loss) showed correlations with beliefs that obesity is under obese persons' control and largely due to lack of willpower, while temporal discounting parameters for monetary rewards did not. Taken together, our weight loss temporal discounting measure demonstrated both convergent and divergent validity, which can be utilized for future obesity research and interventions.

Tonic hyper-connectivity of reward neurocircuitry in obese children

OBJECTIVE

Obese children demonstrate less activation in prefrontal regions associated with self-control and inhibition when presented with food cues and advertisements. This study evaluates the differences between obese and healthy weight children in resting-state functional connectivity to these brain regions.

METHODS

Seed regions in bilateral middle frontal gyri were chosen based on previous task-based analysis showing differences between obese and healthy weight children's responses to food-associated stimuli. Functional connectivity to these seed regions was measured in resting-state scans collected in obese and lean children undergoing fMRI.

RESULTS

Obese children exhibited greater resting-state functional connectivity than healthy weight children between the left middle frontal gyrus and reward-related regions in the left ventromedial prefrontal cortex, as well as the left lateral OFC.

CONCLUSION

Previously published results demonstrated that obese children exhibit less activity in brain regions associated with self-control when viewing motivationally salient food advertisements. Here, it is shown that the obese children also have tonically greater input to these self-control regions from reward neurocircuitry. The greater functional connectivity between reward and self-control regions, in conjunction with weaker activation of self-control neurocircuitry, may render these children more susceptible to food advertisements, placing them at elevated risk for over-feeding and obesity.

Polypharmacy in multiple sclerosis: relationship with fatigue, perceived cognition, and objective cognitive performance

OBJECTIVE

Patients with multiple sclerosis (MS) commonly use a variety of medications to slow disease progression, alleviate symptoms, and treat comorbid conditions. Polypharmacy has been linked to adverse outcomes in other patient groups, but has not been studied extensively in MS. We investigated the impact of polypharmacy on fatigue, objective neuropsychological performance, and subjective cognitive impairment in a sample of patients with MS.

METHODS

MS patients (n=85) completed a medication inventory, self-report questionnaires, and a battery of neurocognitive tests. MS patients with polypharmacy were compared to MS patients without polypharmacy, using multivariate analysis of covariance (MANCOVA).

RESULTS

After controlling for disease characteristics, MS patients with polypharmacy (n=28) exhibited prospective memory deficits and reported significantly more fatigue and subjective cognitive problems than MS patients without polypharmacy.

CONCLUSION

Clinicians and patients should carefully weigh the costs and benefits of prescribing multiple medications, as these may contribute to iatrogenic fatigue and cognitive problems in MS. Moreover, researchers should account for polypharmacy when conducting studies examining fatigue and cognition in MS.

Robust relation between temporal discounting rates and body mass

When given the choice between $100 today and $110 in 1 week, certain people are more likely to choose the immediate, yet smaller reward. The present study examined the relations between temporal discounting rate and body mass while accounting for important demographic variables, depressive symptoms, and behavioral inhibition and approach. After having their heights and weights measured, 100 healthy adults completed the Monetary Choice Questionnaire, the Beck Depression Inventory-II, and the Behavioral Inhibition Scale/Behavioral Approach Scale. Overweight and obese participants exhibited higher temporal discounting rates than underweight and healthy weight participants. Temporal discounting rates decreased as the magnitude of the delayed reward increased, even when other variables known to impact temporal discounting rate (i.e., age, education level, and annual household income) were used as covariates. A higher body mass was strongly related to choosing a more immediate monetary reward. Additional research is needed to determine whether consideration-of-future-consequences interventions, or perhaps cognitive control interventions, could be effective in obesity intervention or prevention programs.

A comparison of functional brain changes associated with surgical versus behavioral weight loss

OBJECTIVE

Few studies have examined brain changes in response to effective weight loss; none have compared different methods of weight-loss intervention. Functional brain changes associated with a behavioral weight loss intervention to those associated with bariatric surgery were compared.

DESIGN AND METHODS

Fifteen obese participants were recruited prior to adjustable gastric banding surgery and 16 obese participants were recruited prior to a behavioral diet intervention. Groups were matched for demographics and amount of weight lost. Functional magnetic resonance imaging scans (visual food motivation paradigm while hungry and following a meal) were conducted before and 12 weeks after surgery/behavioral intervention.

RESULTS

When compared to bariatric patients in the premeal analyses, behavioral dieters showed increased activation to food images in right medial prefrontal cortex (PFC) and left precuneus following weight loss. When compared to behavioral dieters, bariatric patients showed increased activation in bilateral temporal cortex following weight loss.

CONCLUSIONS

Behavioral dieters showed increased responses to food cues in medial PFC-a region associated with valuation and processing of self-referent information-when compared to bariatric patients. Bariatric patients showed increased responses to food cues in brain regions associated with higher level perception-when compared to behavioral dieters. The method of weight loss determines unique changes in brain function.

Branding and a child's brain: an fMRI study of neural responses to logos

Branding and advertising have a powerful effect on both familiarity and preference for products, yet no neuroimaging studies have examined neural response to logos in children. Food advertising is particularly pervasive and effective in manipulating choices in children. The purpose of this study was to examine how healthy children’s brains respond to common food and other logos. A pilot validation study was first conducted with 32 children to select the most culturally familiar logos, and to match food and non-food logos on valence and intensity. A new sample of 17 healthy weight children were then scanned using functional magnetic resonance imaging. Food logos compared to baseline were associated with increased activation in orbitofrontal cortex and inferior prefrontal cortex. Compared to non-food logos, food logos elicited increased activation in posterior cingulate cortex. Results confirmed that food logos activate some brain regions in children known to be associated with motivation. This marks the first study in children to examine brain responses to culturally familiar logos. Considering the pervasiveness of advertising, research should further investigate how children respond at the neural level to marketing.

Importance of reward and prefrontal circuitry in hunger and satiety: Prader-Willi syndrome vs simple obesity

Background

The majority of research on obesity has focused primarily on clinical features (eating behavior, adiposity measures), or peripheral appetite-regulatory peptides (leptin, ghrelin). However, recent functional neuroimaging studies have demonstrated that some reward circuitry regions which are associated with appetite-regulatory hormones are also involved in the development and maintenance of obesity. Prader-Willi syndrome (PWS), characterized by hyperphagia and hyperghrelinemia reflecting multi-system dysfunction in inhibitory and satiety mechanisms, serves as an extreme model of genetic obesity. Simple (non-PWS) obesity (OB) represents an obesity control state.

Objective

This study investigated subcortical food motivation circuitry and prefrontal inhibitory circuitry functioning in response to food stimuli before and after eating in individuals with PWS compared with OB. We hypothesized that groups would differ in limbic regions (i.e., hypothalamus, amygdala) and prefrontal regions associated with cognitive control [i.e., dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC)] after eating.

Design and Participants

Fourteen individuals with PWS, 14 BMI- and age-matched individuals with OB, and 15 age-matched healthy-weight controls (HWC) viewed food and non-food images while undergoing functional MRI before (pre-meal) and after (post-meal) eating. Using SPM8, group contrasts were tested for hypothesized regions: hypothalamus, nucleus accumbens (NAc), amygdala, hippocampus, OFC, medial PFC, and DLPFC.

Results

Compared with OB and HWC, PWS demonstrated higher activity in reward/limbic regions (NAc, amygdala) and lower activity in hypothalamus and hippocampus, in response to food (vs. non-food) images pre-meal. Post-meal, PWS exhibited higher subcortical activation (hypothalamus, amygdala, hippocampus) compared to OB and HWC. OB showed significantly higher activity versus PWS and HWC in cortical regions (DLPFC, OFC) associated with inhibitory control.

Conclusion

In PWS compared with obesity per se, results suggest hyperactivations in subcortical reward circuitry and hypoactivations in cortical inhibitory regions after eating, which provides evidence of neural substrates associated with variable abnormal food motivation phenotypes in PWS and simple obesity.

Neural correlates of pediatric obesity

OBJECTIVE

Childhood obesity rates have increased over the last 40 years and have a detrimental impact on public health. While the causes of the obesity epidemic are complex, obesity ultimately arises from chronic imbalances between energy intake and expenditure. An emerging area of research in obesity has focused on the role of the brain in evaluating the rewarding properties of food and making decisions about what and how much to eat.

METHOD

This article reviews recent scientific literature regarding the brain's role in pediatric food motivation and childhood obesity.

RESULTS

The article will begin by reviewing some of the recent literature discussing challenges associated with neuroimaging in children and the relevant developmental brain changes that occur in childhood and adolescence. The article will then review studies regarding neural mechanisms of food motivation and the ability to delay gratification in children and how these responses differ in obese compared to healthy weight children.

CONCLUSION

Increasing our understanding about how brain function and behavior may differ in children will inform future research, obesity prevention, and interventions targeting childhood obesity.

Ability to delay gratification and BMI in preadolescence

Delay of gratification tasks require an individual to forgo an immediate reward and wait for a more desirable delayed reward. This study used an ecologically valid measure of delayed gratification to test the hypothesis that preadolescents with higher BMI would be less likely to delay gratification. Healthy Hawks is a 12-week educational/behavioral obesity intervention at the University of Kansas Medical Center. Each week, children earn a point if they complete their goals worksheet. They can spend that point immediately on a small toy prize or save points to use on a larger prize. We retrospectively calculated the percentage of points saved over the 12 weeks for 59 children (28 females) ages 8-12 years old (mean = 10.29 ± 1.39). Spearman correlation revealed that higher BMI percentile was associated with reduced point savings (r = 0.33, P = 0.01). Similarly, obese preadolescents saved significantly fewer points than healthy weight (HW) and overweight preadolescents (t (57) = 3.14, P < 0.01). Results from our ecologically valid measure support the theory that obese children are less likely to delay gratification than overweight and HW children. Even for nonfood rewards, preadolescent children with higher BMIs prefer the immediate reward over a delayed, larger reward. This has implications for developing specific strategies within obesity treatments aimed at improving delayed gratification.

Obese children show hyperactivation to food pictures in brain networks linked to motivation, reward and cognitive control

OBJECTIVE

To investigate the neural mechanisms of food motivation in children and adolescents, and examine brain activation differences between healthy weight (HW) and obese participants.

SUBJECTS

Ten HW children (ages 11-16; BMI < 85%ile) and 10 obese children (ages 10-17; BMI >95%ile) matched for age, gender and years of education.

MEASUREMENTS

Functional magnetic resonance imaging (fMRI) scans were conducted twice: when participants were hungry (pre-meal) and immediately after a standardized meal (post-meal). During the fMRI scans, the participants passively viewed blocked images of food, non-food (animals) and blurred baseline control.

RESULTS

Both groups of children showed brain activation to food images in the limbic and paralimbic regions (PFC/OFC). The obese group showed significantly greater activation to food pictures in the PFC (pre-meal) and OFC (post-meal) than the HW group. In addition, the obese group showed less post-meal reduction of activation (vs pre-meal) in the PFC, limbic and the reward-processing regions, including the nucleus accumbens.

CONCLUSION

Limbic and paralimbic activation in high food motivation states was noted in both groups of participants. However, obese children were hyper-responsive to food stimuli as compared with HW children. In addition, unlike HW children, brain activations in response to food stimuli in obese children failed to diminish significantly after eating. This study provides initial evidence that obesity, even among children, is associated with abnormalities in neural networks involved in food motivation, and that the origins of neural circuitry dysfunction associated with obesity may begin early in life.

Neural mechanisms associated with food motivation in obese and healthy weight adults

One out of three adults in the United States is clinically obese. Excess food intake is associated with food motivation, which has been found to be higher in obese compared to healthy weight (HW) individuals. Little is known, however, regarding the neural mechanisms associated with food motivation in obese compared to HW adults. The current study used functional magnetic resonance imaging (fMRI) to examine changes in the hemodynamic response in obese and HW adults while they viewed food and nonfood images in premeal and postmeal states. During the premeal condition, obese participants showed increased activation, compared to HW participants, in anterior cingulate cortex (ACC) and medial prefrontal cortex (MPFC). Moreover, in the obese group, self-report measures of disinhibition were negatively correlated with premeal ACC activations and self-report measures of hunger were positively correlated with premeal MPFC activations. During the postmeal condition, obese participants also showed greater activation than HW participants in the MPFC. These results indicate that brain function associated with food motivation differs in obese and HW adults and may have implications for understanding brain mechanisms contributing to overeating and obesity, and variability in response to diet interventions.

Working memory in obstructive sleep apnea: construct validity and treatment effects

STUDY OBJECTIVE

To better understand the effects of obstructive sleep apnea (OSA) on working memory performance. We first examined the construct validity of a working memory task (the 2-Back task) and its relationship to other tests of cognitive functioning, and then determined the effects of positive airway pressure (PAP) treatment on measures of both working memory and its related component processes.

METHODS

Fifty-six participants with OSA were administered cognitive tests of working memory and related subordinate cognitive processes prior to initiation of PAP treatment and at a 3-month follow-up visit. Objective monitors were employed to measure PAP treatment adherence. Statistical analyses were conducted to examine treatment adherence and cognitive performance over time.

RESULTS

Performance on the 2-Back task was statistically correlated with both a second working memory task (PASAT) and all subordinate cognitive measures. Participants were separated into high and low PAP adherence groups using a median split of 4 hours of PAP use per night. Repeated measures ANOVAs demonstrated that high adherers performed better across time on both tests of working memory (2-Back: F46 = 4.73, p <0.04; PASAT: F46 = 4.92, p <0.04) whereas low adherers performed more poorly. There were no treatment effects for any other cognitive measure.

CONCLUSIONS

The 2-Back task demonstrated adequate construct validity as a measurement of working memory in individuals with OSA. Our treatment adherence findings suggest that the construct of working memory is more sensitive to the effects OSA treatment than are any of its subordinate cognitive processes.