Executive function in weight loss and weight loss maintenance: a conceptual review and novel neuropsychological model of weight control

Children's executive functioning and health behaviors across pediatric life stages and ecological contexts

Executive functioning (EF) has been linked to chronic disease risk in children. Health behaviors are thought to partially explain this association. The current cross-sectional study evaluated specific domains of EF and varied health behaviors in three pediatric life stages. Pediatric participants (early childhood n = 2074, Mage = 6.4 ± 0.9 y; middle childhood n = 3230, Mage = 9.6 ± 1.2 y; adolescence n = 1416, Mage = 15.2 ± 1.7 y) were part of the Environmental influences on Child Health Outcomes (ECHO) Program. They completed neurocognitive tasks measuring cognitive flexibility, behavioral inhibition, and working memory. Parent- and/or child-report measures of dietary intake, physical activity, sleep duration and quality, income, and positive parenting were also collected. Neighborhood crime and greenspace were calculated from publicly available census-tract level indices. After adjusting for study site, child body mass index, and demographics, working memory was related in the hypothesized direction to several dietary behaviors within all pediatric life stages. Working memory and cognitive flexibility were positively related to physical activity in middle childhood and adolescence. In adolescence, behavioral inhibition was positively related to physical activity and inversely related to sugar-sweetened beverage and total caloric intake. Associations with sleep were all non-significant. All significant associations reflected small effect sizes. Income, positive parenting, greenspace, and crime did not significantly influence any of the EF-health behavior associations. Findings highlight the need to consider EF domains, specific health behaviors, and developmental stage in creating intervention strategies that target EF to improve health behaviors. The small effect sizes reinforce the need for multi-tiered interventions to maximize health.

A brief bout of moderate intensity physical activity improves preadolescent children's behavioral inhibition but does not change their energy intake

Children in rural communities consume more energy-dense foods relative to their urban peers. Identifying effective interventions for improving energy intake patterns are needed to address these geographic disparities. The primary aim of this study was to harness the benefits of physical activity on children's executive functioning to see if these improvements lead to acute changes in eating behaviors. In a randomized crossover design, 91 preadolescent (8-10y; M age = 9.48 ± 0.85; 50.5% female; 85.7% White, 9.9% Multiracial, 9.9% Hispanic) children (86% rural) completed a 20-minute physical activity condition (moderate intensity walking) and time-matched sedentary condition (reading and/or coloring) ~ 14 days apart. Immediately following each condition, participants completed a behavioral inhibition task and then eating behaviors (total energy intake, relative energy intake, snack intake) were measured during a multi-array buffet test meal. After adjusting for period and order effects, body fat (measured via DXA), and depressive symptoms, participants experienced significant small improvements in their behavioral inhibition following the physical activity versus sedentary condition (p = 0.04, Hedge's g = 0.198). Eating behaviors did not vary by condition, nor did improvements in behavioral inhibition function as a mediator (ps > 0.09). Thus, in preadolescent children, small improvements in behavioral inhibition from physical activity do not produce acute improvements in energy intake. Additional research is needed to clarify whether the duration and/or intensity of physical activity sessions would produce different results in this age group, and whether intervention approaches and corresponding mechanisms of change vary by individual factors, like age and degree of food cue responsivity.

The Longitudinal Interplay between Adverse Peer Experiences and Self-Regulation Facets: A Prospective Analysis during Middle Childhood

Positive peer experiences and self-regulation (SR) skills are crucial for children's healthy development, but little is known about how they interact during middle childhood. Therefore, we examined the prospective links between adverse peer experiences (APEs) and SR, drawing from the dataset of the PIER study. Across three measurement points, 1654 children aged 6-11 (T1), 7-11 (T2), and 9-13 years (T3) were included. We assessed the SR facets updating, flexibility, inhibition, emotional reactivity, inhibitory control, and planning using computerized tasks, parent- and teacher-reports. The latent variable of APEs consisted of measures of peer victimization and peer rejection assessed via self-, parent-, and teacher-report. Separate cross-lagged panel models were calculated, investigating the interplay of each SR facet and APEs. Results indicated that experiencing more APEs at T1 predicted higher emotional reactivity, and lower inhibition, inhibitory control, updating, and flexibility at T2. More APEs at T2 predicted higher emotional reactivity and lower planning at T3. Lower inhibition, updating, and flexibility at T2 predicted more APEs at T3. Accordingly, we found a negative bidirectional relationship between inhibition, updating, and flexibility with APEs. Our findings highlight that during middle childhood more APEs predict lower SR, which in turn predicts more experiences of peer victimization and rejection.

Dynamical alterations of brain function and gut microbiome in weight loss

Objective

Intermittent energy restriction (IER) is an effective weight loss strategy. However, little is known about the dynamic effects of IER on the brain-gut-microbiome axis.

Methods

In this study, a total of 25 obese individuals successfully lost weight after a 2-month IER intervention. FMRI was used to determine the activity of brain regions. Metagenomic sequencing was performed to identify differentially abundant gut microbes and pathways in from fecal samples.

Results

Our results showed that IER longitudinally reduced the activity of obese-related brain regions at different timepoints, including the inferior frontal orbital gyrus in the cognitive control circuit, the putamen in the emotion and learning circuit, and the anterior cingulate cortex in the sensory circuit. IER longitudinally reduced E. coli abundance across multiple timepoints while elevating the abundance of obesity-related Faecalibacterium prausnitzii, Parabacteroides distasonis, and Bacterokles uniformis. Correlation analysis revealed longitudinally correlations between gut bacteria abundance alterations and brain activity changes.

Conclusions

There was dynamical alteration of BGM axis (the communication of E. coli with specific brain regions) during the weight loss under the IER.

Engineering Virtuous health habits using Emotion and Neurocognition: Flexibility for Lifestyle Optimization and Weight management (EVEN FLOW)

Interventions to preserve functional independence in older adults are critically needed to optimize 'successful aging' among the large and increasing population of older adults in the United States. For most aging adults, the management of chronic diseases is the most common and impactful risk factor for loss of functional independence. Chronic disease management inherently involves the learning and adaptation of new behaviors, such as adopting or modifying physical activity habits and managing weight. Despite the importance of chronic disease management in older adults, vanishingly few individuals optimally manage their health behavior in the service of chronic disease stabilization to preserve functional independence. Contemporary conceptual models of chronic disease management and health habit theory suggest that this lack of optimal management may result from an underappreciated distinction within the health behavior literature: the behavioral domains critical for initiation of new behaviors (Initiation Phase) are largely distinct from those that facilitate their maintenance (Maintenance Phase). Psychological factors, particularly experiential acceptance and trait levels of openness are critical to engagement with new health behaviors, willingness to make difficult lifestyle changes, and the ability to tolerate aversive affective responses in the process. Cognitive factors, particularly executive function, are critical to learning new skills, using them effectively across different areas of life and contextual demands, and updating of skills to facilitate behavioral maintenance. Emerging data therefore suggests that individuals with greater executive function are better able to sustain behavior changes, which in turn protects against cognitive decline. In addition, social and structural supports of behavior change serve a critical buffering role across phases of behavior change. The present review attempts to address these gaps by proposing a novel biobehavioral intervention framework that incorporates both individual-level and social support system-level variables for the purpose of treatment tailoring. Our intervention framework triangulates on the central importance of self-regulatory functioning, proposing that both cognitive and psychological mechanisms ultimately influence an individuals' ability to engage in different aspects of self-management (individual level) in the service of maintaining independence. Importantly, the proposed linkages of cognitive and affective functioning align with emerging individual difference frameworks, suggesting that lower levels of cognitive and/or psychological flexibility represent an intermediate phenotype of risk. Individuals exhibiting self-regulatory lapses either due to the inability to regulate their emotional responses or due to the presence of executive functioning impairments are therefore the most likely to require assistance to preserve functional independence. In addition, these vulnerabilities will be more easily observable for individuals requiring greater complexity of self-management behavioral demands (e.g. complexity of medication regimen) and/or with lesser social support. Our proposed framework also intuits several distinct intervention pathways based on the profile of self-regulatory behaviors: we propose that individuals with intact affect regulation and impaired executive function will preferentially respond to 'top-down' training approaches (e.g., strategy and process work). Individuals with intact executive function and impaired affect regulation will respond to 'bottom-up' approaches (e.g., graded exposure). And individuals with impairments in both may require treatments targeting caregiving or structural supports, particularly in the context of elevated behavioral demands.

A Pilot Goal-Oriented Episodic Future Thinking Weight Loss Intervention for Low-Income Overweight or Obese Young Mothers

BACKGROUND

Episodic future thinking (EFT) has shown efficacy in laboratory settings. We conducted a pilot goal-oriented EFT (GoEFT) intervention in a real-world setting to help low-income overweight or obese mothers lose weight. This paper presents intervention acceptability and efficacy.

METHODS

The study used a single-group, before-after design. During the 3-week intervention, participants (N = 15) completed weekly web-based lessons and online health coaching sessions to manage stress and emotion, eat healthier, and be more physically active. Participants completed online surveys at baseline and immediately after the intervention. They also completed an interview to evaluate intervention acceptability. We applied paired t-tests to evaluate efficacy and used content analysis to discover interview themes.

RESULTS

Participants consistently identified the intervention as acceptable, noting the usefulness of pre-written goals, GoEFT strategies, and goal progress evaluations. The intervention effectively promoted weight loss (d = -0.69), fruit and vegetable intake (d = 0.45-0.49), and emotion control (d = 0.71). It also reduced fat (d = -0.51) and added sugar intake (d = -0.48) and alleviated stress (d = -0.52). Moreover, the intervention increased autonomous motivation (d = 0.75-0.88) and self-efficacy (d = 0.46-0.61).

CONCLUSION

The GoEFT intervention was acceptable to participants, showing strong preliminary efficacy.

Self-regulation as a resource for coping with developmental challenges during middle childhood and adolescence: the prospective longitudinal PIERYOUTH-study

BACKGROUND

Self-regulation (SR) as the ability to regulate one's own physical state, emotions, cognitions, and behavior, is considered to play a pivotal role in the concurrent and subsequent mental and physical health of an individual. Although SR skills encompass numerous sub-facets, previous research has often focused on only one or a few of these sub-facets, and only rarely on adolescence. Therefore, little is known about the development of the sub-facets, their interplay, and their specific contributions to future developmental outcomes, particularly in adolescence. To fill these research gaps, this study aims to prospectively examine (1) the development of SR and (2) their influence on adolescent-specific developmental outcomes in a large community sample.

METHODS/DESIGN

Based on previously collected data from the Potsdam Intrapersonal Developmental Risk (PIER) study with three measurement points, the present prospective, longitudinal study aims to add a fourth measurement point (PIER_YOUTH). We aim to retain at least 1074 participants now between 16 and 23 years of the initially 1657 participants (6-11 years of age at the first measurement point in 2012/2013; 52.2% female). The study will continue to follow a multi-method (questionnaires, physiological assessments, performance-based computer tasks), multi-facet (assessing various domains of SR), and multi-rater (self-, parent-, and teacher-report) approach. In addition, a broad range of adolescent-specific developmental outcomes is considered. In doing so, we will cover the development of SR and relevant outcomes over the period of 10 years. In addition, we intend to conduct a fifth measurement point (given prolonged funding) to investigate development up to young adulthood.

DISCUSSION

With its broad and multimethodological approach, PIER_YOUTH aims to contribute to a deeper understanding of the development and role of various SR sub-facets from middle childhood to adolescence. The large sample size and low drop-out rates in the first three measurements points form a sound database for our present prospective research. Trial registration German Clinical Trials Register, registration number DRKS00030847.

Spatiotemporal profile of altered neural reactivity to food images in obesity: Reward system is altered automatically and predicts efficacy of weight loss intervention

Introduction

Obesity presents a significant public health problem. Brain plays a central role in etiology and maintenance of obesity. Prior neuroimaging studies have found that individuals with obesity exhibit altered neural responses to images of food within the brain reward system and related brain networks. However, little is known about the dynamics of these neural responses or their relationship to later weight change. In particular, it is unknown if in obesity, the altered reward response to food images emerges early and automatically, or later, in the controlled stage of processing. It also remains unclear if the pretreatment reward system reactivity to food images is predictive of subsequent weight loss intervention outcome.

Methods

In this study, we presented high-calorie and low-calorie food, and nonfood images to individuals with obesity, who were then prescribed lifestyle changes, and matched normal-weight controls, and examined neural reactivity using magnetoencephalography (MEG). We performed whole-brain analysis to explore and characterize large-scale dynamics of brain systems affected in obesity, and tested two specific hypotheses: (1) in obese individuals, the altered reward system reactivity to food images occurs early and automatically, and (2) pretreatment reward system reactivity predicts the outcome of lifestyle weight loss intervention, with reduced activity associated with successful weight loss.

Results

We identified a distributed set of brain regions and their precise temporal dynamics that showed altered response patterns in obesity. Specifically, we found reduced neural reactivity to food images in brain networks of reward and cognitive control, and elevated reactivity in regions of attentional control and visual processing. The hypoactivity in reward system emerged early, in the automatic stage of processing (< 150 ms post-stimulus). Reduced reward and attention responsivity, and elevated neural cognitive control were predictive of weight loss after six months in treatment.

Discussion

In summary, we have identified, for the first time with high temporal resolution, the large-scale dynamics of brain reactivity to food images in obese versus normal-weight individuals, and have confirmed both our hypotheses. These findings have important implications for our understanding of neurocognition and eating behavior in obesity, and can facilitate development of novel integrated treatment strategies, including tailored cognitive-behavioral and pharmacological therapies.

Educational quality may be a closer correlate of cardiometabolic health than educational attainment

Educational quality may be a closer correlate of physical health than more commonly used measures of educational attainment (e.g., years in school). We examined whether a widely-used performance-based measure of educational quality is more closely associated with cardiometabolic health than educational attainment (highest level of education completed), and whether perceived control (smaller sample only), executive functioning (both samples), and health literacy (smaller sample only) link educational quality to cardiometabolic health. In two samples (N = 98 and N = 586) collected from different regions of the US, educational quality was associated with cardiometabolic health above and beyond educational attainment, other demographic factors (age, ethnoracial category, sex), and fluid intelligence. Counter to expectations, neither perceived control, executive function, nor health literacy significantly mediated the association between educational quality and cardiometabolic health. Findings add to the growing literature suggesting that current operationalizations of the construct of education likely underestimate the association between education and multiple forms of health. To the extent that educational programs may have been overlooked based on the apparent size of associations with outcomes, such actions may have been premature.

The Neglected Factor in the Relationship between Executive Functioning and Obesity: The Role of Motor Control

BACKGROUND

The association between obesity and executive functions (EFs) is highly controversial. It has been suggested that waist circumference (WC), compared to body mass index (BMI), is a better indicator of fat mass and EFs in obesity. Moreover, according to the viewpoint that the brain's functional architecture meets the need for interactive behavior, we hypothesize that the relationship between EFs and body weight might be mediated by the motor performance.

METHODS

General executive functioning (frontal assessment battery-15), additional cognitive subdomains (trail making test and digit span backward), and motor performance (finger tapping task) were assessed in a sample that included 330 volunteers (192 females, M age = 45.98 years, SD = 17.70, range = 18-86 years).

RESULTS

Hierarchical multiple regression analysis indicated that the FAB15 score and FTT negatively predicted WC but not BMI. A subsequent mediation analysis highlighted that the indirect effect of FAB15 on WC through finger tapping was statistically significant.

CONCLUSIONS

Our results suggest that WC, as compared to BMI, is a more effective measure for studying the association between EFs and body weight. Still, we found that the motor domain partially mediates the dynamics of such a relationship.

Functional Relationship between Inhibitory Control, Cognitive Flexibility, Psychomotor Speed and Obesity

In the last decades, it has been proposed that executive functions may be particularly vulnerable to weight-related issues. However, evidence on the matter is mixed, especially when the effects of sociodemographic variables are weighted. Thus, the current study aimed at further examining the relationship between executive functions and obesity. To this aim, we compared treatment-seeking overweight, obese, and morbidly obese patients with normal-weight control participants. We examined general executive functioning (Frontal Assessment Battery−15) and different executive subdomains (e.g., inhibitory control, verbal fluency, and psychomotor speed) in a clinical sample including 208 outpatients with different degrees of BMI (52 overweight, BMI 25−30, M age = 34.38; 76 obese, BMI 30−40, M age = 38.00; 80 morbidly obese, BMI > 40, M age = 36.20). Ninety-six normal-weight subjects served as controls. No difference on executive scores was detected when obese patients were compared with over- or normal-weight subjects. Morbidly obese patients reported lower performance on executive scores than obese, overweight, and normal-weight subjects. Between-group difference emerged also when relevant covariates were taken into account. Our results support the view that morbid obesity is associated with lower executive performance, also considering the critical role exerted by sociodemographic (i.e., sex, age, and education) variables. Our results support the view that executive functioning should be accounted into the management of the obese patient because of non-negligible clinical relevance in diagnostic, therapeutic, and prognostic terms.

Executive Function-Related Improvements on a Commercial CBT-Based Weight Management Intervention: Pilot Randomized Controlled Trial

Executive functioning is a key component involved in many of the processes necessary for effective weight management behavior change (e.g., setting goals). Cognitive behavioral therapy (CBT) and third-wave CBT (e.g., mindfulness) are considered first-line treatments for obesity, but it is unknown to what extent they can improve or sustain executive functioning in a generalized weight management intervention. This pilot randomized controlled trial examined if a CBT-based generalized weight management intervention would affect executive functioning and executive function-related brain activity in individuals with obesity or overweight. Participants were randomized to an intervention condition (N = 24) that received the Noom Weight program or to a control group (N = 26) receiving weekly educational newsletters. EEG measurements were taken during Flanker, Stroop, and N-back tasks at baseline and months 1 through 4. After 4 months, the intervention condition evidenced greater accuracy over time on the Flanker and Stroop tasks and, to a lesser extent, neural markers of executive function compared to the control group. The intervention condition also lost more weight than controls (−7.1 pounds vs. +1.0 pounds). Given mixed evidence on whether weight management interventions, particularly CBT-based weight management interventions, are associated with changes in markers of executive function, this pilot study contributes preliminary evidence that a multicomponent CBT-based weight management intervention (i.e., that which provides both support for weight management and is based on CBT) can help individuals sustain executive function over 4 months compared to controls.

Executive Functions in Overweight and Obese Treatment-Seeking Patients: Cross-Sectional Data and Longitudinal Perspectives

BACKGROUND

Recent evidence suggests that a higher body weight may be linked to cognitive impairment in different domains involving executive/frontal functioning. However, challenging results are also available. Accordingly, our study was designed to verify whether (i) poor executive functions are related to a higher body weight and (ii) executive functioning could contribute to weight loss in treatment-seeking overweight and obese patients.

METHODS

We examined general executive functioning, inhibitory control, verbal fluency, and psychomotor speed in a sample including 104 overweight and obese patients. Forty-eight normal-weight subjects participated in the study as controls.

RESULTS

Univariate Analysis of Variance showed that obese patients obtained lower scores than overweight and normal-weight subjects in all executive measures, except for errors in the Stroop test. However, when sociodemographic variables entered the model as covariates, no between-group difference was detected. Furthermore, an adjusted multiple linear regression model highlighted no relationship between weight loss and executive scores at baseline.

CONCLUSIONS

Our results provide further evidence for the lack of association between obesity and the executive domains investigated. Conflicting findings from previous literature may likely be due to the unchecked confounding effects exerted by sociodemographic variables and inclusion/exclusion criteria.

Influence of Weight Loss on Cognitive Functions: A Pilot Study of a Multidisciplinary Intervention Program for Obesity Treatment

There is a relationship between obesity and cognitive functioning. Our aim was to assess weight loss influence on global cognition and executive functioning (EF) in adults with obesity under a multidisciplinary weight loss program. In this six-month longitudinal study, we assessed 81 adults (age < 50 years) with body mass index (BMI) ≥ 30. EF and global cognitive performance were evaluated with the Montreal Cognitive Assessment (MoCA), Neuropsychological Battery of Executive Functions (BANFE-2) and Trail Making Test-Part B (TMT-B). Median age was 40.0 years (IQR: 31.5−47, 61% women), and the median BMI was 41.4 (IQR: 36.7−45.9). At a six-month follow-up, the mean weight loss was 2.67% (29.6% of patients achieved ≥5% weight loss). There was an improvement in EF evaluated with BANFE (p = 0.0024) and global cognition with MoCA (p = 0.0024). Women experienced more remarkable change, especially in EF. Weight loss did not correlate with cognitive performance, except for TMT-B (r-0.258, p = 0.026). In the regression analysis, only years of education predicted the MoCA score. This study showed that patients improved cognitive performance during the follow-up; nevertheless, the magnitude of weight loss did not correlate with cognitive improvement. Future studies are warranted to demonstrate if patients achieving ≥5% weight loss can improve cognition, secondary to weight loss.

The role of cognitive flexibility in weight loss after severe obesity surgery-A retrospective study

Cognitive flexibility (CF) is a fundamental skill for behavioural regulation and adaptation during the weight-loss process. Research suggests that bariatric surgery (BS) candidates underperform consistently in the Wisconsin Card Sorting Test (WCST), which is a neuropsychological instrument that measures this ability. The current study explored the predictive value of preoperative performance in WCST CF dimensions alongside relevant psychological factors on weight loss after BS. The sample comprised 100 female patients who underwent BS in a public hospital in Lisbon, Portugal. We collected data using the WCST, the Hopkins Symptom Checklist-90-Revised (SCL-90-R), and the Binge Eating Scale (BES). Multiple linear regression (MLR) analyses were performed to obtain explanatory models of total weight loss at 12- and 24-postoperative months (TWL₁ and TWL₂ , respectively). MLR identified the number of preservative responses as a highly significant predictor of TWL₁ (p < 0.01)_, and the SCL-90-R obsession-compulsion and anxiety indices as highly significant predictors of TWL₁ and TWL₂ (p < 0.01). The number of preservative responses was a relevant predictor of weight loss at 12 months. Persisting in maladaptive cognitive strategies was associated with a lesser weight loss during the important period after BS that requires the adoption new lifestyle habits.

Higher general executive functions predicts lower body mass index by mitigating avoidance behaviors

BACKGROUND

The present study examines the relationship between obesity, executive functions, and body image in a nonclinical population from southern Italy.

METHODS

General executive functioning (Frontal Assessment Battery-15), and body image disturbances (Body Uneasiness Test) were assessed in a sample including 255 participants (138 females, M age = 43.51 years, SD = 17.94, range = 18-86 years; M body mass index (BMI) = 26.21, SD = 4.32, range = 18.03-38.79).

FINDINGS

Multiple Linear Regression Analysis indicated that age, years of education, FAB15 score, body image concerns, and avoidance predicted the variance of BMI. A subsequent mediation analysis highlighted that the indirect effect of FAB15 on BMI through avoidance was statistically significant.

INTERPRETATION

Our results suggest that more performing executive functioning predicts a decrease in BMI that is partially due to the mitigation of avoidance behaviors.

Preexisting Executive Function Deficits and Change in Health Behaviors During the COVID-19 Pandemic

BACKGROUND

Executive functions (EF) support engagement in goal-directed behaviors, including several health behaviors. Stressful and cognitively demanding events can disrupt EFs and interfere with health behavior, possibly to a greater extent in those with preexisting EF deficits. This study examined the association between preexisting EF deficits and subsequent negative changes in eating patterns, physical activity, sedentariness, and alcohol/substance use during the COVID-19 pandemic.

METHOD

Participants were 374 young adults in a follow-up study of the longitudinal, multisite Study of Early Child Care and Youth Development (SECCYD). Preexisting EF deficits were assessed with the Barkley Deficits in Executive Function Scales-Short Form, and personally impactful negative changes in four health behaviors (physical activity, unhealthy eating, sedentary time, alcohol/substance use) during the COVID-19 pandemic were subsequently assessed with the Epidemic-Pandemic Impacts Inventory.

RESULTS

In ordered logistic regression models, higher preexisting total EF deficits were associated with greater negative impactful changes in physical activity and unhealthy eating, independent of sociodemographic variables, obesity, and (as relevant) accelerometer-based physical activity and pre-COVID-19 diet quality. Socioeconomic status moderated the association between total EF deficits and impactful change in alcohol/substance use, with EF deficits linked to greater impactful change in alcohol/substance use only in higher socioeconomic strata.

CONCLUSION

Individuals with preexisting EF deficits appear more vulnerable to the negative impact of the COVID-19 pandemic on several key health behaviors. As the pandemic unfolds, strategies may be needed to identify those with EF deficits (e.g., screening tools) and provide them with tailored support for chronic disease risk reduction.

The Impact of Restrictive and Non-restrictive Dietary Weight Loss Interventions on Neurobehavioral Factors Related to Body Weight Control: the Gaps and Challenges

PURPOSE OF REVIEW

Restrictive diets, such as low-calorie diets, are difficult to maintain in the long term. For this reason, their popularity has decreased compared to non-restrictive approaches, which instead promote healthy eating strategies. Since both strategies may entail different neurobiological mechanisms, this review will examine the current evidence on the effects of restrictive and non-restrictive interventions on neurobehavioral factors.

RECENT FINDINGS

Restrictive diets appear to improve eating behaviors, and the evidence reviewed argues against the notion that they may worsen the severity of binge eating. Moreover, they may lead to short-term changes in brain structure and improvements in cerebrovascular markers which, in turn, could impact eating behaviors. Non-restrictive interventions may have a positive effect on weight management and eating behaviors. However, evidence of their neural effects is scarce. Small sample sizes, short follow-ups, and the absence of control groups are limitations of the studies targeting both interventions. Rigorous long-term randomized studies are needed to examine the neurobehavioral effects of restrictive and non-restrictive approaches.

Identifying behavioral types of dietary lapse from a mobile weight loss program: Preliminary investigation from a secondary data analysis

Success in behavioral weight loss (BWL) programs depends on adherence to the recommended diet to reduce caloric intake. Dietary lapses (i.e., deviations from the BWL diet) occur frequently and can adversely affect weight loss outcomes. Research indicates that lapse behavior is heterogenous; there are many eating behaviors that could constitute a dietary lapse, but they are rarely studied as distinct contributors to weight outcomes. This secondary analysis aims to evaluate six behavioral lapse types during a 10-week mobile BWL program (eating a large portion, eating when not intended, eating an off-plan food, planned lapse, being unaware of caloric content, and endorsing multiple types of lapse). Associations between weekly behavioral lapse type frequency and weekly weight loss were investigated, and predictive contextual characteristics (psychological, behavioral, and environmental triggers for lapse) and individual difference (e.g., age, gender) factors were examined across lapse types. Participants (N = 121) with overweight/obesity (M_BMI = 34.51; 84.3% female; 69.4% White) used a mobile BWL program for 10 weeks, self-weighed weekly using Bluetooth scales, completed daily ecological momentary assessment of lapse behavior and contextual characteristics, and completed a baseline demographics questionnaire. Linear mixed models revealed significant negative associations between unplanned lapses and percent weight loss. Unplanned lapses from eating a large portion, eating when not intended, and having multiple "types" were significantly negatively associated with weekly percent weight loss. A lasso regression showed that behavioral lapse types share many similar stable factors, with other factors being unique to specific lapse types. Results add to the prior literature on lapses and weight loss in BWL and provide preliminary evidence that behavioral lapse types could aid in understanding adherence behavior and developing precision medicine tools to improve dietary adherence.

Executive Functioning, Depressive Symptoms, and Intervention Engagement in a Sample of Adolescents Enrolled in a Weight Management Program

Purpose: This study examines how baseline demographics, psychosocial characteristics, and intervention delivery predict engagement among adolescents with overweight and obesity seeking treatment. Methods: Data originates from a multisite randomized control trial evaluating the efficacy of an app-based weight loss intervention, compared with standard in-clinic model in adolescents with overweight and obesity. Participants were randomized to one of the three arms: (1) AppCoach, (2) AppAlone, or (3) Control. Demographic, executive functioning (EF), and depression questionnaires were completed at baseline. Percent engagement was compared within and between groups defined by demographics and depressive symptoms. Quantile regression was used to evaluate the association between age and EF on percent engagement. Results: Baseline demographics were not associated with engagement within or between groups. Neither baseline self-reported depressive symptoms (p = 0.244) nor deficits in EF (p = 0.34) were predictors of engagement. Univariate analysis found that the control arm had the highest engagement (83%) compared with AppCoach (63.5%) and AppAlone (22.5%, p = 0.02). Hispanic ethnicity was predictive of higher engagement in the control arm (p = 0.02). On multivariate quartile regression no other baseline characteristics were significant predictors of engagement. Conclusion: Baseline demographics and individual psychosocial characteristics were not related to engagement in this cohort. The intervention arm that required parental involvement resulted in the greatest engagement suggesting that family involvement may overshadow individual behavioral phenotype and thus promote better engagement. Further investigation is needed to understand how program delivery can be leveraged to optimize treatment engagement and outcomes in adolescence. Clinical Trial Registration number: NCT03500835.

Improving Serious Games to Tackle Childhood Obesity

Childhood obesity has become a global public health issue. Today, there are opportunities to promote health through technological devices such as serious games. Despite the major advancement of this field of research, the use of serious games as a validated intervention in clinical practice requires further clarifications on some methodological aspects. In this perspective article, we report the pros and cons of existing serious games. Besides, we attempt to propose a new methodology of design of a serious game that could help to cope with childhood obesity. The proposed idea consists of a serious game in virtual reality based on enjoyment, movement, education, and executive functioning (EF) training. Longitudinal studies and solid research protocol would certainly ensure consistency and aid interpretation.

Executive Functions and Body Weight at Different Ages: A Preliminary Study

Recently, researchers have focused their attention on the role of cognitive processes on eating habits and body weight changes. Few studies have examined the relationship between the first stages of overweight and executive functions (EFs), excluding obesity conditions. This study is aimed to detect the involvement of the EFs and their predictive role on body mass index (BMI) in a sample of healthy individuals from childhood to young adulthood with a cross-sectional design. One-hundred and sixty-six healthy students were recruited from different Italian public schools: 46 children (age range: 7–11), 50 adolescents (age range: 15–18), 70 young adults (age range: 19–30). BMI was used to evaluate body weight and different EFs tasks were used to assess the EFs domains of inhibition, updating and shifting. After adjusting BMI for age, a hierarchical multiple linear regression was carried out for each EFs task. Pearson’s r correlations were reported for each of the age subgroups. Motor disinhibition was associated with greater BMI in the overall sample. Higher BMI was related to poorer set-shifting in adolescence and poorer motor inhibition in young adulthood, but higher BMI was not associated with EFs in childhood. Differences in the development of EFs over time may influence weight changes over time through different responses to food and eating behavior.

Perspective: Time-Restricted Eating Compared with Caloric Restriction: Potential Facilitators and Barriers of Long-Term Weight Loss Maintenance

A growing body of literature examines the potential benefits of a time-based diet strategy referred to as time-restricted eating (TRE). TRE, a type of intermittent fasting, restricts the time of eating to a window of 4-12 h/d but allows ad libitum intake during eating windows. Although TRE diets do not overtly attempt to reduce energy intake, preliminary evidence from small studies suggests that TRE can lead to concomitant reduction in total energy, improvements in metabolic health, and weight loss. Unique features of the TRE diet strategy may facilitate adherence and long-term weight loss maintenance. In this Perspective, we explore the potential multilevel (i.e., biological, behavioral, psychosocial, environmental) facilitators and barriers of TRE for long-term weight loss maintenance in comparison with the more commonly used diet strategy, caloric restriction (CR). Compared with CR, TRE may facilitate weight loss maintenance by counteracting physiological adaptations to weight loss (biological), allowing for usual dietary preferences to be maintained (behavioral), preserving executive functioning (psychosocial), and enabling individuals to withstand situational pressures to overeat (environmental). However, TRE may also pose unique barriers to weight loss maintenance, particularly for individuals with poor baseline diet quality, internal or social pressures to eat outside selected windows (e.g., grazers), and competing demands that interfere with the scheduling of eating. Future studies of TRE in free-living individuals should consider the multiple levels of influence impacting long-term adherence and weight loss maintenance. Ultimately, TRE could be one strategy in a toolkit of tailored diet strategies to support metabolic health and weight loss maintenance.

Delay of Gratification Predicts Eating in the Absence of Hunger in Preschool-Aged Children

Poor ability to regulate one's own food intake based on hunger cues may encourage children to eat beyond satiety, leading to increased risk of diet-related diseases. Self-regulation has multiple forms, yet no one has directly measured the degree to which different domains of self-regulation predict overeating in young children. The present study investigated how three domains of self-regulation (i.e., appetitive self-regulation, inhibitory control, and attentional control) predicted eating in the absence of hunger (EAH) in a community sample of 47 preschool-aged children (M age = 4.93, SD = 0.86). Appetitive self-regulation, as measured using a delay of gratification task, was significantly and negatively associated with EAH 1 year later (p < 0.5). Measures of inhibitory and attentional control did not significantly predict EAH. These results suggest that food-related self-regulation may be a better predictor of overeating behaviors than general measures of self-regulation.

Executive function in individuals with clinically significant weight loss via behavioral intervention

BACKGROUND

Executive function (EF) is associated with obesity development and self-management. Individuals who demonstrate or self-report poorer EF performance tend to have poorer short-term outcomes in obesity treatment. There may be distinct behavioral self-management strategies and EF domains related to initial weight loss as compared to weight loss maintenance.

OBJECTIVE

To characterize EF in individuals who achieved clinically significant weight loss via behavioral intervention and examine potential differences in EF between those who maintained versus regained lost weight.

METHODS

Participants who previously achieved ≥5% weight loss via lifestyle intervention were included (N = 44). "Maintainers" (n = 16) maintained this minimum level of weight loss for ≥1 year. "Regainers" (n = 28) regained some or all initially lost weight. Performance-based EF, intelligence quotient, health literacy, depression, anxiety, binge eating, demographics, and medical/weight history were assessed using a cross-sectional design. Descriptive statistics and age-, gender-, education-adjusted reference ranges were used to characterize EF. Analyses of covariance were conducted to examine EF differences between maintainers and regainers.

RESULTS

The sample consisted primarily of females with obesity over age 50. Approximately half self-identified as African-American. Decision-making performance was better in maintainers than regainers (p = 0.003, partη2 = 0.19). There were no differences between maintainers and regainers in inhibitory control, verbal fluency, planning/organization, cognitive flexibility, or working memory (ps > 0.05, partη2s = 0.003-0.07). At least 75% of the sample demonstrated average-above average EF test performance, indicated by scaled scores ≥13 or t-scores > 60.

CONCLUSIONS

Most individuals with obesity who achieved clinically significant weight loss via behavioral intervention had average to above average EF. Individuals who maintained (vs. regained) their lost weight performed better on tests of decision-making.

Cognitive remediation-enabled cognitive behaviour therapy for obesity: a case series

PURPOSE

Despite varied treatment effects, weight recidivism is common and typically associated with the abandonment of prescribed weight management strategies. Literature suggests that difficulty with weight management is associated with deficits in executive functioning, in particular cognitive flexibility and response inhibition, the neurocognitive processes that are involved in goal-directed behaviours, such as dietary adherence. These processes are overlooked by mainstream weight loss programmes. The aim of the study was to assess the effectiveness of a cognitive remediation-enabled cognitive behaviour therapy (CR-CBT) in addressing the neurocognitive, psychological and behavioural correlates of weight loss. It was hypothesised that CR-CBT would improve cognitive flexibility and response inhibition, reduce binge eating, aid weight loss and improve metabolic health.

METHODS

Four adults with obesity (body mass index > 30 kg/m²) received 7 weeks of manualised CR-CBT and were assessed via a case series analysis at baseline, end of treatment and 3-month follow-up. Treatment included 3 weekly 90-min group-based behaviour weight loss sessions for 3 weeks, followed by twice-weekly 50-min individualised CR-CBT sessions for 4 weeks.

RESULTS

Cognitive remediation-enabled cognitive behaviour therapy produced improvements in response inhibition and cognitive flexibility, and reductions in binge eating frequency, weight, and metabolic health readings between baseline and 3-month follow-up.

CONCLUSIONS

This is the first study to assess the effectiveness of CR-CBT in the treatment of obesity. Preliminary indications of treatment success are discussed with respect to study limitations. In light of these results, we recommend further investigation via a randomised control trial (RCT).

LEVEL OF EVIDENCE

Level IV, case series.

A Conceptual Model of Long-Term Weight Loss Maintenance: The Importance of Cognitive, Empirical and Computational Approaches

Living with obesity is related to numerous negative health outcomes, including various cancers, type II diabetes, and cardiovascular disease. Although much is known about the factors associated with obesity, and a range of weight loss interventions have been established, changing health-related behaviours to positively affect obesity outcomes has proven difficult. In this paper, we first draw together major factors that have emerged within the literature on weight loss to describe a new conceptual framework of long-term weight loss maintenance. Key to this framework is the suggestion that increased positive social support influences a reduction in psychosocial stress, and that this has the effect of promoting better executive functioning which in turn facilitates the development of healthy habits and the breaking of unhealthy habits, leading to improved ongoing maintenance of weight loss. We then outline how the use of computational approaches are an essential next step, to more rigorously test conceptual frameworks, such as the one we propose, and the benefits that a mixture of conceptual, empirical and computational approaches offer to the field of health psychology.

Food reward sensitivity, impulsivity, and weight change during and after a 3-month weight loss program

Background

Greater sensitivity to food rewards and higher levels of impulsivity (and an interaction between these variables, termed “reinforcement pathology”) have been associated with obesity in cross-sectional studies. Less is known regarding how these constructs may impact attempts at weight loss or longer-term weight loss maintenance.

Methods

We provided 75 adults (69%Female, 84%White, age = 50.8y, BMI = 31.2kg/m²) with a 3-month Internet-based weight loss program and assessed weight, food reward sensitivity (via the Power of Food Scale [PFS]), and impulsivity (via Go No-Go [GNG] and Delay Discounting [DD] computer tasks) at baseline and at Months 3, 6, 9, and 12. No additional intervention was provided Months 3–12. Multi-level mixed-effect models were used to examine changes in PFS, GNG, and DD over time and associations between these measures and weight loss/regain.

Results

Participants lost 6.0±1.1kg Months 0–3 and regained 2.4±1.1kg Months 3–12. Across time points, higher PFS scores were associated with higher weight, p = .007; however, there were no significant associations between GNG or DD and weight nor between the interactions of PFS and GNG or DD and weight, ps>.05. There were significant decreases from Months 0–3 in PFS, GNG, and DD, ps < .05; however, neither baseline values nor changes were significantly associated with weight change and there were no significant associations between the interactions of PFS and GNG or DD and weight change, ps>.05.

Conclusion

Results demonstrated an association between food reward sensitivity and weight. Further, decreases in both food reward sensitivity and impulsivity were observed during an initial weight loss program, but neither baseline levels nor improvements were associated with weight change. Taken together, results suggest that the constructs of food reward sensitivity, impulsivity, and reinforcement pathology may have limited clinical utility within behavioral weight management interventions. Future intervention studies should examine whether food-related impulsivity tasks lead to a similar pattern of results.

Preoperative inhibitory control predicts weight loss 1 year after bariatric surgery

OBJECTIVE

Executive function (EF) and, in particular, inhibitory control have been associated with weight loss (WL) in behavioural WL treatment for obesity. Few studies have focused on the relationship between preoperative inhibitory control and post-operative WL following bariatric surgery, and the potential mediating role of maladaptive eating behaviours is unclear. The aim of this study was to investigate preoperative executive function as a predictor of WL at 1 year following bariatric surgery. Additionally, we aimed to explore the mediating role of postoperative compulsive grazing in the relationship between inhibitory control and WL.

METHOD

A prospective observational study in which participants completed neuropsychological testing 30 days before and 1 year following surgery (n = 61/80; 76% follow-up). Participants were 80% female, with an average age of 41 years. Approximately 54% underwent gastric bypass, 26% gastric sleeve and 20% had one anastomosis gastric bypass. Regression analyses were employed to examine the relationship between preoperative EF and percentage total weight loss (%TWL), and structural equation modelling was used to examine compulsive grazing as a mediator.

RESULTS

After adjusting for control variables, preoperative inhibitory control explained 8% of the variance in %TWL (p ≤ 0.05). Preoperative working memory was not significantly associated with %TWL. Postoperative compulsive grazing was significantly associated with %TWL (p ≤ 0.05), but did not mediate the association between preoperative inhibitory control and %TWL.

CONCLUSION

The results suggest that preoperative inhibitory control performance is a relevant predictor of postoperative WL and that compulsive grazing is a maladaptive eating behaviour that warrants clinical attention after surgery.

Brain Connectivity, and Hormonal and Behavioral Correlates of Sustained Weight Loss in Obese Patients after Laparoscopic Sleeve Gastrectomy

The biological mediators that support cognitive-control and long-term weight-loss after laparoscopic sleeve gastrectomy (LSG) remain unclear. We measured peripheral appetitive hormones and brain functional-connectivity (FC) using magnetic-resonance-imaging with food cue-reactivity task in 25 obese participants at pre, 1 month, and 6 month after LSG, and compared with 30 normal weight controls. We also used diffusion-tensor-imaging to explore whether LSG increases brain structural-connectivity (SC) of regions involved in food cue-reactivity. LSG significantly decreased BMI, craving for high-calorie food cues, ghrelin, insulin, and leptin levels, and increased self-reported cognitive-control of eating behavior. LSG increased FC between the right dorsolateral prefrontal cortex (DLPFC) and the pregenual anterior cingulate cortex (pgACC) and increased SC between DLPFC and ACC at 1 month and 6 month after LSG. Reduction in BMI correlated negatively with increased FC of right DLPFC-pgACC at 1 month and with increased SC of DLPFC-ACC at 1 month and 6 month after LSG. Reduction in craving for high-calorie food cues correlated negatively with increased FC of DLPFC-pgACC at 6 month after LSG. Additionally, SC of DLPFC-ACC mediated the relationship between lower ghrelin levels and greater cognitive control. These findings provide evidence that LSG improved functional and structural connectivity in prefrontal regions, which contribute to enhanced cognitive-control and sustained weight-loss following surgery.

Episodic future thinking, delay discounting, and exercise during weight loss maintenance: The PACE trial

OBJECTIVES

Weight loss maintenance (WLM) is the next major challenge in obesity treatment. While most individuals who lose weight intend to keep their weight off, weight regain is common. Temporal Self-Regulation Theory posits that whether intentions lead to behavior depends on self-regulatory capacity, including delay discounting (DD; the tendency to discount a larger future reward in favor of a smaller immediate reward). Episodic Future Thinking (EFT; mental imagery of a future event for which a health goal is important) may improve DD and promote behavior change. Described herein is a trial protocol designed to examine whether EFT improves DD within the context of weight loss maintenance.

METHOD

Participants who lose ≥5% of initial body weight in an online behavioral weight loss intervention will be randomly assigned to a standard weight loss maintenance program (WLM-STD) or a weight loss maintenance program plus EFT (WLM + EFT). Both interventions involve periodic phone and in-person treatment sessions. Participants in WLM + EFT will engage in daily EFT training via smartphone. To control for contact, participants in WLM-STD will engage in daily Healthy Thinking (reviewing strategies for weight management) on their smartphone. Our primary hypothesis is that WLM + EFT will yield better improvements in DD compared to WLM-STD. We will also explore whether DD mediates the relationship between intervention allocation and physical activity (secondary outcome). Weight and contextual variables will be explored.

CONCLUSIONS

This study is the first to test whether EFT improves DD within the context of weight loss maintenance; results from this experimental medicine approach could have important implications for understanding the impact of both EFT and DD on sustained behavior change. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Linking Grazing to Inhibition and Goal-Directed Behaviour in Obesity With and Without Eating Disorder Features

Recent models of obesity and eating behaviour have implicated both automatic responding to food-related cues and executive functioning in driving dietary choice. This study aimed to relate grazing severity to high weight with and without significant eating disorder features via the effects of inhibition and degree of goal-directed behaviour, in persons with obesity with and without significant eating disorder features compared to healthy controls. Forty-four participants with obesity (43.1% endorsing marked eating disorder features), and 43 healthy-weight age- and sex-matched participants (N = 87; 67.8% female, age = 28.57 (8.70; 18.18–58.34) years, BMI = 29.18 (7.80; 18.65–51.95) kg/m2) completed demographic and eating disorder-related questionnaires, a neuropsychological task of inhibition and an instrumental decision-making task. Bootstrapped serial mediation analyses were performed to examine the effect of group on grazing via goal-directed behaviour and inhibition. While significant differences existed between the groups in terms of inhibition, goal-directed behaviour and grazing severity, the effect of group on grazing severity was not found to be mediated by the degree of behavioural goal-directedness and inhibition. Therefore, :in persons with obesity with or without eating disorder symptoms, putative relationships between a reduced inhibitory profile and/or behaviour that is less flexible and goal-directed and eating behaviours such as grazing, remain unclear.

Neural correlates of future weight loss reveal a possible role for brain-gastric interactions

Lifestyle dietary interventions are an essential practice in treating obesity, hence neural factors that may assist in predicting individual treatment success are of great significance. Here, in a prospective, open-label, three arms study, we examined the correlation between brain resting-state functional connectivity measured at baseline and weight loss following 6 months of lifestyle intervention in 92 overweight participants. We report a robust subnetwork composed mainly of sensory and motor cortical regions, whose edges correlated with future weight loss. This effect was found regardless of intervention group. Importantly, this main finding was further corroborated using a stringent connectivity-based prediction model assessed with cross-validation thus attesting to its robustness. The engagement of senso-motor regions in this subnetwork is consistent with the over-sensitivity to food cues theory of weight regulation. Finally, we tested an additional hypothesis regarding the role of brain-gastric interaction in this subnetwork, considering recent findings of a cortical network synchronized with gastric activity. Accordingly, we found a significant spatial overlap with the subnetwork reported in the present study. Moreover, power in the gastric basal electric frequency within our reported subnetwork negatively correlated with future weight loss. This finding was specific to the weight loss related subnetwork and to the gastric basal frequency. These findings should be further corroborated by combining direct recordings of gastric activity in future studies. Taken together, these intriguing results may have important implications for our understanding of the etiology of obesity and the mechanism of response to dietary intervention.

Executive Functioning as a Predictor of Weight Loss and Physical Activity Outcomes

BACKGROUND

Executive functioning, which is fundamental for carrying out goal-directed behaviors, may be an underappreciated predictor of outcomes in lifestyle modification programs for adults with obesity.

PURPOSE

This study tested the hypotheses that higher levels of baseline executive functioning would predict greater weight loss and physical activity after 6 months of behavioral treatment.

METHODS

Participants (N = 320) were recruited from the community and provided with 16 treatment sessions. Executive functioning was measured with the tower task component of the Delis-Kaplan Executive Function System (D-KEFS). At months 0 and 6, weight was measured in the clinic and physical activity was measured with tri-axial accelerometers.

RESULTS

Baseline D-KEFS achievement score, rule violations, and completion time significantly predicted weight loss at 6 months. For example, among participants without any rule violations (n = 162), weight loss averaged 11.0%, while those with rule violations (n = 158) averaged 8.7% weight loss. Rule violations also significantly predicted physical activity at 6 months. Among participants without any rule violations, physical activity at 6 months averaged 169.8 min/week, versus 127.2 min/week among those with rule violations.

CONCLUSIONS

Particular aspects of executive functioning may predict the relative ease or difficulty of changing eating and exercise-related behaviors, albeit with small effect sizes. This study is the first to our knowledge to detect a predictive relationship between components of executive functioning and objectively measured physical activity in adult lifestyle modification, and one of the first to predict weight loss in adults using an objective measure of executive functioning.

CLINICALTRIALS.GOV REGISTRATION NUMBER

NCT02363010.

The Clinical Obesity Maintenance Model: A Theoretical Framework for Bariatric Psychology

Ranked highly in its association with serious medical comorbidities, obesity, a rapidly growing epidemic worldwide, poses a significant socio-economic burden. While bariatric procedures offer the most efficacious treatment for weight loss, a subset of patients risk weight recidivism. Due to the heterogeneity of obesity, it is likely that there are phenotypes or sub-groups of patients that require evidence-based psychological support to produce more sustainable outcomes. So far, however, characteristics of patients have not led to a personalized treatment algorithm for bariatric surgery. Maintenance of weight loss following bariatric surgery requires long-term modification of eating behaviors and physical activity. A recent Clinical Obesity Maintenance Model (COMM) proposed a conceptual framework of salient constructs, including the role of habit, behavioral clusters, emotion dysregulation, mood, health literacy, and executive function as interconnected drivers of obesity maintaining behaviors relevant to the field of bariatric psychology. The primary aim of this concise review is to bring together emerging findings from experimental and epidemiological studies relating to the COMM constructs that may inform the assessment and follow up of bariatric surgery. We also aim to explain the phenotypes that need to be understood and screened prior to bariatric surgery to enable better pre-surgery intervention and optimum post-surgery response.

Child neurobiology impacts success in family-based behavioral treatment for children with obesity

Background and Objectives:

Family-based behavioral treatment (FBT) is the recommended treatment for children with common obesity. However, there is a large variability in short- and long-term treatment response and mechanisms for unsuccessful treatment outcomes are not fully understood. In this study, we tested if brain response to visual food cues among children with obesity before treatment predicted weight or behavioral outcomes during a 6-mo. behavioral weight management program and/or long-term relative weight maintenance over a 1-year follow-up period.

Subjects and Methods:

Thirty-seven children with obesity (age 9–11y, 62% male) who entered active FBT (attended 2 or more sessions) and had outcome data. Brain activation was assessed at pre-treatment by functional magnetic resonance imaging across an a priori set of appetite-processing brain regions that included the ventral and dorsal striatum, medial orbitofrontal cortex, amygdala, substantia nigra/ventral tegmental area and insula in response to viewing food images before and after a standardized meal.

Results:

Children with more robust reductions in brain activation to high-calorie food cue images following a meal had greater declines in BMI z-score during FBT (r= 0.42; 95% CI: 0.09, 0.66; P=0.02) and greater improvements in Healthy Eating Index scores (r= −0.41; 95% CI: −0.67, −0.06; P=0.02). In whole-brain analyses, greater activation in the ventromedial prefrontal cortex, specifically by high-calorie food cues, was predictive of better treatment outcomes (whole-brain cluster corrected P=0.02). There were no significant predictors of relative weight maintenance and initial behavioral or hormonal measures did not predict FBT outcomes.

Conclusions:

Children’s brain responses to a meal prior to obesity treatment were related to treatment-based weight outcomes, suggesting that neurophysiologic factors and appetitive drive, more so than initial hormone status or behavioral characteristics, limit intervention success.

Acute coordinative exercise ameliorates general and food-cue related cognitive function in obese adolescents

Whether the acute coordinative exercise could affect the inhibitory control and food-cue related attention in obese adolescents remains understudied. Therefore, this study used the Stroop test and the food-cue related Stroop test to explore the impacts of 20 min of acute coordinative exercise on the cognitive tests involving inhibitory control and attentional bias towards food-cue related stimuli, respectively, in obese adolescents. Thirty-eight obese adolescents (mean age = 14.63 ± 0.69 years) were equally divided into exercise and control groups. The cognitive tests (i.e., the Stroop test and the food-cue related Stroop test) and hunger scores were conducted and assessed before and after an intervention. The exercise group had significantly larger negative pre-post response time difference in the congruent (-1.04 ± 0.29 ms) and incongruent (-5.76 ± 1.66 ms) conditions of the Stroop test than the control group (ps < 0.01), and a smaller post-interference (1.13 ± 0.14) than the pre-interference (1.31 ± 0.14, p = 0.04). Moreover, a significantly larger negative pre-post response time difference on the food-cue related Stroop test was observed in the exercise group (-4.42 ± 7.20 ms) than the control group (1.76 ± 8.37 ms, p = 0.02). Collectively, an acute coordinative exercise session could induce superior inhibitory control and less attentional bias towards food-cue related stimuli in obese adolescents.

Cognitive Performance as Predictor and Outcome of Adolescent Bariatric Surgery: A Nonrandomized Pilot Study

Objectives

Evidence in adults suggests that improvements in cognitive performance may follow weight loss resulting from bariatric surgery, and baseline cognitive performance may be associated with weight loss following surgery. This has not been evaluated in adolescents.

Method

Participants were 38 adolescents of age 14-21 years composed of three groups: (1) 12 adolescents with severe obesity who received vertical sleeve gastrectomy during the study (VSG); (2) 14 adolescents with severe obesity who were wait-listed for VSG (WL); and (3) 12 healthy weight controls (HC). Participants completed testing of visual memory, verbal memory, and executive functioning at baseline (T1), which occurred presurgery for the VSG group, and approximately 4 months after baseline (T2). Body mass index (BMI) was assessed at T1, T2, and additionally at 6 months following VSG for the adolescents who received surgery.

Results

Although there was evidence of greater improvement for the VSG as compared with WL and HC groups in visual and verbal memory, group differences did not reach significance and effect sizes were small (η2 < 0.01). There was a significant positive association between indices of baseline executive functioning and excess BMI loss at 6 months postsurgery.

Conclusions

This small pilot study showed no significant differences by group in cognitive performance post-VSG. There was a significant association of baseline cognitive performance with weight loss outcomes. Given the very preliminary nature of these results in a small sample, future research should examine these relationships in a larger sample and evaluate mechanisms of these associations (e.g., insulin resistance, sleep, physical activity).

The Executive Functions in Overweight and Obesity: A Systematic Review of Neuropsychological Cross-Sectional and Longitudinal Studies

Background: The increasing incidence of people affected by overweight or obesity is a significant health problem. The knowledge of the factors which influences the inappropriate eating behaviors causing excessive body fat is an essential goal for the research. Overweight and obesity are significant risk factors for many health diseases, such as cardiovascular problems, diabetes. Recently, many studies have focused on the relationship between body weight and cognitive processes. Objectives: This systematic review is aimed to investigate the existence and the nature of the relationship between excessive body weight (overweight/obesity) and executive functions, analyzing cross-sectional, and longitudinal studies in order to verify the evidence of a possible causality between these variables. Methods: The review was carried out according to the PRISMA-Statement, through systematic searches in the scientific databases PubMed, Medline, PsychInfo, and PsycArticles. The studies selected examined performance on executive tasks by participants with overweight or obesity, aged between 5 and 70 years. Studies examining eating disorders or obesity resulting from other medical problems were excluded. Furthermore, the results of studies using a cross-sectional design and those using a longitudinal one were separately investigated. Results: Sixty-three cross-sectional studies and twenty-eight longitudinal studies that met our inclusion and exclusion criteria were analyzed. The results confirmed the presence of a relation between executive functions and overweight/obesity, although the directionality of this relation was not clear; nor did any single executive function emerge as being more involved than others in this relation. Despite this, there was evidence of a reciprocal influence between executive functions and overweight/obesity. Conclusions: This systematic review underlines the presence of a relationship between executive functions and overweight/obesity. Moreover, it seems to suggest a bidirectional trend in this relationship that could be the cause of the failure of interventions for weight reduction. The results of this review highlight the importance of a theoretical model able to consider all the main variables of interest, with the aim to structuring integrated approaches to solve the overweight/obesity problems.

Minority Stress, Emotion Regulation, and Executive Function: An Experimental Investigation of Gay and Lesbian Adults

Minority stress is associated with emotional, cognitive, and health consequences for sexual minority individuals. Mechanisms remain poorly understood. Theory and preliminary evidence suggests that stress associated with minority identity results in negative emotions and attempts at suppression, which may contribute to depletion of executive function. This study was an experimental investigation of gay and lesbian adults (N = 141). Participants engaged in a stressful interpersonal task with a confederate with anti-gay or pro-gay attitudes. We examined how condition affected executive function, along with potential mediators (state anger, anxiety, expressive suppression). Contrary to hypotheses, participants in the anti-gay condition showed better postmanipulation cognitive performance than the pro-gay condition. This effect was partially mediated by anger. Participants in the anti-gay condition reported greater attempts at suppression, but this variable did not emerge as a mediator. This study was the first to experimentally manipulate exposure to anti-gay attitudes and measure effects on executive function.

Does executive function moderate the relation between momentary affective and physical states and subsequent dietary lapse? An EMA investigation

The study explored whether baseline individual differences in executive function (EF) affect the relation between elevations in internal states and subsequent likelihood of lapsing from a dietary prescription. Participants were 189 adults with overweight/obesity in a behavioral weight loss treatment who completed a neuropsychological EF task at intake and a 2-week EMA protocol measuring internal states and dietary lapses at start of treatment. Generalized estimating equations found relations between momentary elevations in tiredness (b = .06, p = .01) and deprivation (b = .06, p = .047) and subsequent likelihood of lapsing were more robust for participants with lower EF, whereas the relation between momentary elevations in boredom and subsequent likelihood of lapsing (b = .04, p = .03) was more robust for participants with higher EF. Results provide support for EF impacting the relation between elevations in internal states and likelihood of dietary lapse, informing the development of personalized behavioral weight loss treatments.

Executive Function, Eating Behavior, and Preoperative Weight Loss in Bariatric Surgery Candidates: An Observational Study

BACKGROUND

Individual differences in executive function may influence eating behavior, weight loss (WL), and WL maintenance in obesity treatment. Executive function, which designates top-down cognitive control processes, has been related to eating behaviors which may impact weight, and has been found to be predictive of WL in both behavioral WL programs and after bariatric surgery. Currently, we lack knowledge on the role of executive function in the period before bariatric surgery. If executive function impacts eating behavior and WL in the preoperative period, it may be a target for clinical attention in this stage.

OBJECTIVES

We aimed to examine the relationship between objective performance-based measures of executive function, eating patterns, and WL in the preoperative period.

METHOD

Baseline data in an ongoing observational longitudinal study of bariatric surgery patients were used. Eighty patients completed neuropsychological testing and self-report questionnaires 4 weeks prior to surgery.

RESULTS

We found that working memory predicted WL before surgery and inhibitory control predicted adherence to dietary recommendations.

CONCLUSION

Our study indicates that executive function may play a role in short-term WL and dietary adherence prior to surgery, suggesting that executive function in the preoperative period deserves an extended research focus.

Group cognitive remediation therapy for adults with obesity prior to behavioural weight loss treatment: study protocol for a randomised controlled superiority study (CRT study)

INTRODUCTION

Individuals with obesity show deficits in executive functioning which have been implicated in decreased weight loss outcome. Preliminary evidence suggests that cognitive remediation therapy (CRT) improves executive functioning and weight loss in obesity. However, confirmatory support, especially for pre-weight loss use, is lacking. The CRT study aims at determining the efficacy of CRT versus no treatment control in patients with obesity before entering behavioural weight loss (BWL) treatment. It is hypothesised that individuals who receive CRT will show better weight loss outcome, improved executive functioning, greater weight loss-related behavioural changes and higher attendance of BWL treatment, 6 and 12 months after cessation of CRT.

METHODS AND ANALYSIS

In a single-centre, assessor-blinded, randomised, two-armed parallel-group superiority trial, 260 adults with body mass index ≥35.0 kg/m2 are centrally randomised to 8-week group-based CRT versus no treatment, before entering BWL treatment. Primary outcome is the amount of weight loss (%) at 6-month follow-up, compared with pre-treatment, derived from measured body weight. Secondary outcomes include improvement in executive functioning post-treatment and in weight loss-related behaviour, mental and physical health, and attendance to BWL treatment at 6-month and 12-month follow-up. Maintenance of weight loss at 12-month follow-up will be determined. Mixed model analyses based on intent-to-treat will be used to compare the CRT and control groups with respect to differences in weight change between pre-treatment and 6-month follow-up. Similar models will be used for analysing 12-month follow-up data and secondary outcomes. Further analyses will include additional covariates to identify predictors of treatment outcome.

ETHICS AND DISSEMINATION

The study was approved by the Ethical Committee of the University of Leipzig (256-15-13072015, version 'Final 1.0 from 28 May 2015). The study results will be disseminated through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

DRKS00009333; Pre-results.

Weight Loss Maintenance: Have We Missed the Brain?

Even though obese individuals often succeed with weight loss, long-term weight loss maintenance remains elusive. Dietary, lifestyle and psychosocial correlates of weight loss maintenance have been researched, yet the nature of maintenance is still poorly understood. Studying the neural processing of weight loss maintainers may provide a much-needed insight towards sustained obesity management. In this narrative review, we evaluate and critically discuss available evidence regarding the food-related neural responses of weight loss maintainers, as opposed to those of obese or lean persons. While research is still ongoing, available data indicate that following weight loss, maintainers exhibit persistent reward related feeling over food, similar to that of obese persons. However, unlike in obese persons, in maintainers, reward-related brain activity appears to be counteracted by subsequently heightened inhibition. These findings suggest that post-dieting, maintainers acquire a certain level of cognitive control which possibly protects them from weight regaining. The prefrontal cortex, as well as the limbic system, encompass key regions of interest for weight loss maintenance, and their contributions to long term successful weight loss should be further explored. Future possibilities and supportive theories are discussed.

Harnessing centred identity transformation to reduce executive function burden for maintenance of health behaviour change: the Maintain IT model

The inability to produce sustainable lifestyle modifications (e.g., physical activity, healthy diet) remains a major barrier to reducing morbidity and mortality from prevalent, preventable conditions. The objective of this paper is to present a model that builds on and extends foundational theory and research to suggest novel approaches that may help to produce lasting behaviour change. The model aims to integrate factors not typically examined together in order to elucidate potential processes underlying a shift from behaviour initiation to long-term maintenance. The central premise of the Maintain IT model builds on approaches demonstrating that in-tact executive function (EF) is critical for health behaviour initiation, for more complex behaviours beyond initiation, and in unsupportive environments and circumstances, but successful recruitment of EF is effortful and prone to error. Enduring changes are more likely if the underlying cognitive processes can become less effortful (non-conscious, automatic). The Maintain IT model posits that a centred identity transformation is one path leading to less effortful processing and facilitating successful recruitment of EF when necessary over the long term, increasing the sustainability of health behaviour change. A conceptual overview of the literature supporting the utility of this integrative model, future directions, and anticipated challenges are presented.

Self-regulation and obesity: the role of executive function and delay discounting in the prediction of weight loss

Obesity rates are rising worldwide. Executive function and delay discounting have been hypothesized to play important roles in the self-regulation of behavior, and may explain variance in weight loss treatment success. First, we compared individuals with obesity (n = 82) to healthy weight controls (n = 71) on behavioral and self-report measures of executive function (working memory, inhibition and shifting) and delay discounting. Secondly, the individuals with obesity took part in a multidisciplinary weight loss program and we examined whether executive function and delay discounting predicted weight change. Individuals with obesity displayed weaker general and food-specific inhibition, and weaker self-reported executive function. Better behavioral working memory and better self-reported inhibition skills in daily life were predictive of greater weight loss. As findings are correlational, future studies should investigate the causal relationship between executive function and weight loss, and test whether intervening on executive function will lead to better prevention and treatment of obesity.