Disordered Eating Attitudes and Behavioral and Neuroelectric Indices of Cognitive Flexibility in Individuals with Overweight and Obesity

A randomized controlled trial modifying insomnia-consistent interpretation bias in students

This study aimed to determine the causal role of insomnia-consistent interpretation bias within the cognitive model of insomnia, by modifying this bias in students experiencing subclinical levels of insomnia and assessing subsequent effects on sleep parameters. A sample of 128 students underwent randomization to receive either a single session of online Cognitive Bias Modification-Interpretation (CBM-I) or a sham training. Participants then tracked their pre-sleep worry and sleep parameters for seven consecutive days. Interpretation bias was assessed using an encoding-recognition task specifically designed for insomnia-related interpretation bias. The CBM-I manipulation utilized ambiguous scenarios to redirect participants away from making insomnia-related interpretations. Results revealed that CBM-I effectively decreased insomnia-consistent interpretation bias compared to the sham treatment, with interpretation bias being absent post-training in the CBM-I group. This reduction did not lead to improvements in pre-sleep worry or any sleep parameters. This study has been the first to investigate the causal role of interpretation bias on symptoms of insomnia. Although results indicated this bias to be modifiable, its causality within the cognitive model proves to be more complicated. Future research focusing on optimization of cognitive bias modifications could shed more light on the effects of biased cognitions on insomnia symptoms.

Examining Relationships between Cognitive Flexibility, Exercise Perceptions, and Cardiovascular Disease Risk Factors

Adults do not engage in enough physical activity. Investigating cognitive and physiological factors related to improving this behavior-and reducing health risks-remains a public health priority. Our objective was to assess whether cognitive flexibility influenced perceptions and choice of exercise programs and whether flexibility was associated with cardiovascular disease (CVD) risk factors. Independent sample groups of college-aged adults (18-24 yrs) participated in two studies. Data were collected on individuals' degree of cognitive flexibility (both self-reported and objectively measured), perceptions and choice of exercise programs, and health status markers known to be associated with CVD (vascular function, muscular strength, and body composition). Vascular function was assessed with a near-infrared spectroscopy device, strength was defined as handgrip, and body composition was estimated via digital circumferences. Self-reported flexibility reliably predicted individuals' choice of exercise program and perceptions of effort required for success on an exercise program. The relationships among CVD risk factors and objectively measured cognitive flexibility were not significant, demonstrating that identifying a healthy individual's degree of performance-based cognitive flexibility does not predict health status. Furthermore, although greater self-reported trait flexibility (rigidity) is known to predict higher (lower) likelihood of physical activity, this finding should not be extrapolated to also assume that flexibility (rigidity), as measured by objective cognitive tests, is associated with reduced CVD risk in healthy adults. We posit a rationale for how understanding cognitive flexibility and rigidity can play an impactful role in improving adherence to exercise prescriptions targeted to reducing risks.

Executive function, behavioral problems, and insulin resistance in adolescents with obesity

OBJECTIVES

In this study, we examined executive function (EF) abilities, behavioral and emotional (BE) issues, and overall quality of life (QoL) of adolescents with obesity and compared them with a control group and also aimed to investigate whether the presence of insulin resistance (IR) is associated with these problems.

METHODS

This cross-sectional study included a sample of 50 adolescents aged 11-18 years with obesity and age- and gender-matched 50 normal weight adolescents who had attended and were treated at the pediatric outpatient clinic. Sociodemographic data were collected through personal interviews with the adolescents and their parents. Measurements of the height and weight, fasting blood glucose, and insulin levels of all adolescents were assessed. In addition, the participants and their parents completed the Kiddo-KINDL, the Strengths and Difficulties Questionnaire, and the Behavior Rating Inventory Scale from Executive Function.

RESULTS

Of the 50 adolescents with obesity, 27 (54.0 %) were girls, and 23 (46.0 %) were boys, with a mean age of 14.06 ± 1.83 years. Adolescents with obesity have more EF deficiencies, BE difficulties, more problems in peer relationships and lower QoL scores than those without obesity. The QoL was worse in girls, adolescents with obesity, and those with IR. Adolescents with obesity and those with and without IR did not differ about EF deficiencies and BE problems.

CONCLUSIONS

Addressing these EF deficits and BE problems in interventions for adolescents who have difficulty adapting to lifestyle changes, an essential part of obesity treatment in clinical practice, may contribute to treatment success.

Loss of control as a transdiagnostic feature in obesity-related eating behaviours: A systematic review

OBJECTIVE

Emerging evidence suggests that loss of control (LOC) may present as a common feature across disordered eating behaviours. However, there has been limited research on the transdiagnostic nature of LOC in this area. The primary aim of this study was to systematically review disordered eating behaviours and measures of LOC in clinical and non-clinical populations.

METHOD

Electronic searches of the relevant databases were conducted. Selected articles were screened for eligibility and assessed for methodological quality.

RESULTS

Thirty-four studies met inclusion criteria. Findings demonstrated that LOC was associated with disordered eating behaviours across bariatric populations, eating disorder populations, and community populations. Specifically, LOC was associated with binge eating (subjective and objective episodes), grazing, night eating, and emotional or stress eating. Findings also revealed that LOC was inconsistently operationalised across studies, with varied approaches to measuring the construct.

CONCLUSION

Overall, the findings from this review provide support for LOC as a transdiagnostic feature of disordered eating behaviours. Future studies should utilise robust multi-method assessments to measure the severity of LOC, which may provide greater insight into how LOC manifests across different eating disorder presentations.

The Association of Obesity and Cardiorespiratory Fitness in Relation to Cognitive Flexibility: An Event-Related Potential Study

This study investigates an association between obesity and cardiorespiratory fitness concerning their potential effects on cognitive flexibility in young adults from behavioral and neuroelectrical perspectives. Eligible young adults (N = 140, 18-25 years) were assigned into one of four groups, according to their status of obesity (i.e., body mass index) and cardiorespiratory fitness levels (i.e., estimated maximal oxygen uptake), namely, normal weight with high cardiorespiratory fitness (NH), obese with high cardiorespiratory fitness (OH), normal weight with low cardiorespiratory fitness (NL), and obese with low cardiorespiratory fitness (OL). The task-switching test was utilized, and its induced endogenous (P3) and exogenous (N1) event-related potential components were recorded. Concerning behavioral indices, the NH demonstrated superior behavioral performance across global switching and local switching of the task-switching test compared to individuals with lower cardiorespiratory fitness and obesity (i.e., NL, OH, and OL). Additionally, the OH demonstrated better performance than the OL during the heterogeneous condition. For neuroelectrical indices, the NH had larger mean P3 amplitudes during global and local switching than the other three groups. A larger N1 amplitude was also observed in the NH during local switching than in the OH group. The findings suggest that cardiorespiratory fitness has beneficial effects on cognitive flexibility, attentional resource allocation, and sensory evaluation in young adults. Furthermore, our research provided novel evidence showing that cardiorespiratory fitness might potentially alleviate the adverse effects of obesity on cognitive flexibility in young adults.

Using event-related potentials to study food-related cognition: An overview of methods and perspectives for future research

Electroencephalography (EEG), and the measure of event-related potentials (ERPs) in particular, are useful methods to study the cognitive and cerebral mechanisms underlying the perception and processing of food cues. Further research on these aspects is necessary to better understand how cognitive functioning may influence food choices in different populations (e.g. obese individuals, individuals with eating disorders). To help researchers in designing future studies, this article provides an overview of the methods used in the current literature on ERPs and food-related cognition. Several methodological aspects are explored to outline interesting perspectives for future research, including discussions on the main experimental tasks used, the cognitive functions assessed (e.g. inhibitory control, attentional processing), the characteristics of the participants recruited (e.g. weight status, eating behaviors), and the stimuli selected (e.g. food pictures, odors). The issues generated by some of these methodological choices are discussed, and a few guidelines are provided.

Transdiagnostic Perspective of Impulsivity and Compulsivity in Obesity: From Cognitive Profile to Self-Reported Dimensions in Clinical Samples with and without Diabetes

Impulsive and compulsive behaviors have both been observed in individuals with obesity. The co-occurrence of obesity and type 2 diabetes (T2D) is more strongly associated with impulsivity, although there are no conclusive results yet. A multidimensional assessment of impulsivity and compulsivity was conducted in individuals with obesity in the absence or presence of T2D, compared with healthy, normal-weight individuals, with highly impulsive patients (gambling disorders), and with highly compulsive patients (anorexia nervosa). Decision making and novelty seeking were used to measure impulsivity, and cognitive flexibility and harm avoidance were used for compulsivity. For impulsivity, patients with obesity and T2D showed poorer decision-making ability compared with healthy individuals. For compulsivity, individuals with only obesity presented less cognitive flexibility and high harm avoidance; these dimensions were not associated with obesity with T2D. This study contributes to the knowledge of the mechanisms associated with diabetes and its association with impulsive–compulsive behaviors, confirming the hypothesis that patients with obesity and T2D would be characterized by higher levels of impulsivity.

Acute Daily Stress, Daily Food Consumption, and the Moderating Effect of Disordered Eating among Adolescents with Overweight/Obesity

Objective: The purpose of this study was to examine the associations between acute daily stress dimensions (frequency, sum) and food intake in adolescents with overweight/obesity, and to explore the potential moderating effect of disordered eating behaviors on these associations. Methods: One hundred eighty-two adolescents with overweight/obesity (65% females; 68.7% non-white; 16.2 ± 1.8 years of age) were included in this analysis. Acute daily stress was measured using the Daily Stress Inventory, and daily caloric intake was measured using a food frequency questionnaire. Disordered eating behavior was assessed using the Eating Attitudes Test (EAT-26). Results: Acute daily stress frequency (B = 0.013 ± 0.003; p < 0.001) and acute daily stress sum (B = 0.003 ± 0.001; p < 0.001) were associated with greater daily caloric intake. Disordered eating behavior moderated the association between acute daily stress frequency and caloric intake (p_interaction = 0.039), with greater daily caloric intake among those with higher levels of disordered eating. Disordered eating behavior did not significantly moderate the association between acute daily stress sum and daily caloric intake (p_interaction = 0.053). Conclusions: These findings suggest that greater exposure to acute daily stressors may increase daily food intake in adolescents with overweight/obesity, with greater susceptibility among those engaging in high levels of disordered eating. Longitudinal research is warranted to elucidate the long-term effect of acute daily stressors and disordered eating on food intake among adolescents with overweight/obesity. The Health and Culture Project is registered at www.clinicaltrials.gov (No. NCT02938663).

Dietary lutein plus zeaxanthin and choline intake is interactively associated with cognitive flexibility in middle-adulthood in adults with overweight and obesity

BACKGROUND

The xanthophyll carotenoids lutein+zeaxanthin and the dietary component choline have been linked to benefits in cognition. However, knowledge on the interactive influence of these dietary components on cognitive function is sparse.

DESIGN

80 middle-aged adults with overweight and obesity (Body Mass Index: (BMI) ≥25.0 kg/m²), completed 7-day diet records, venous blood draws, heterochromatic flicker photometry, assessment of intelligence quotient (IQ), and a cognitive flexibility task while undergoing electroencephalographic recording for event-related potential (ERP) extraction. Multiplicative interaction terms and hierarchical linear regressions, controlling for age, BMI, sex, annual household income, and IQ were utilized to assess independent and interactive contributions of dietary and biomarker data on Switch task outcomes.

RESULTS

Higher intake of lutein+zeaxanthin and choline was associated interactively, but not independently, with faster reaction time (RT), after controlling for pertinent covariates. Dietary intake of lutein+zeaxanthin and choline was associated with serum lutein concentrations, but not with plasma choline metabolites nor macular pigmentation. Plasma phosphatidylcholine (PC) concentrations were associated with higher accuracy in Switch trials, while no other biomarkers were associated with cognitive outcomes. Dietary intake and biomarker data were not related to the N2 nor P3 ERP component.

CONCLUSIONS

Among a sample of adults with overweight and obesity, greater intake of choline and lutein+zeaxanthin was associated with faster performance on a cognitive flexibility task. Future work examining methods of increasing consumption of both of these dietary components as a possible means of improving or maintaining cognitive flexibility among adults with overweight and obesity is therefore warranted.

Sex-Dependent Wheel Running Effects on High Fat Diet Preference, Metabolic Outcomes, and Performance on the Barnes Maze in Rats

Excessive and prolonged intake of highly palatable, high fat (HF) foods contributes to the pathogenesis of obesity, metabolic syndrome, and cognitive impairment. Exercise can restore energy homeostasis and suppress HF diet preference in rats. However, it is unclear if exercise confers similar protection against the detrimental outcomes associated with a chronic HF diet preference and feeding in both sexes. We used our wheel running (WR) and two-diet choice (chow vs. HF) paradigm to investigate the efficacy of exercise in reversing HF diet-associated metabolic and cognitive dysregulation in rats, hypothesizing that beneficial effects of exercise would be more pronounced in males. All WR rats showed HF diet avoidance upon running initiation, and males, but not females, had a prolonged reduction in HF diet preference. Moreover, exercise only improved glucose tolerance and insulin profile in males. Compared to sedentary controls, all WR rats improved learning to escape on the Barnes maze. Only WR females increased errors made during subsequent reversal learning trials, indicating a sex-dependent effect of exercise on behavioral flexibility. Taken together, our results suggest that exercise is more effective at attenuating HF-associated metabolic deficits in males, and highlights the importance of developing sex-specific treatment interventions for obesity and cognitive dysfunction.

Adolescent stress: A predictor of dieting behaviors in youth with overweight/obesity

OBJECTIVE

To examine associations between psychological stress and dieting behavior along with the heterogeneity of this association by gender and race in a diverse sample of adolescents with overweight/obesity.

METHODS

One hundred and sixty-one adolescents between the ages of 13-19 years of age with overweight/obesity (65% female; 53% non-Hispanic black/47% non-Hispanic white; age: 16.7 ± 1.7 years) were recruited from Southeast MI and included in this analysis. Psychological stress was measured using the Perceived Stress Scale, and dieting behavior was assessed using the dieting subscale from the Eating Attitudes Test (EAT-26) questionnaire. Multivariable linear regression models were conducted to examine the association between psychological stress and dieting behavior by gender and race.

RESULTS

Psychological stress was significantly associated with dieting (β = 0.18 ± 0.06; p < 0.01), with greater stress associated with greater frequency of dieting behavior. This relationship remained significant (β = 0.15 ± 0.06; p = 0.016), even when controlling for covariates (age, body fat, gender, race, and pubertal development). There were no statistically significant differences in the association of psychological stress and disordered eating indices by gender or race/ethnicity (p's > 0.05).

CONCLUSIONS

Increased psychological stress is associated with increased dieting behavior among adolescents with overweight/obesity. These findings suggest that psychological stress equally affects dieting behavior among adolescents with overweight/obesity, regardless of gender and race. Future studies should seek to identify the unique sources of psychological stress that contribute to increased dieting behavior among adolescents with overweight/obesity.

Eating Disorders and Obesity: The Challenge for Our Times

Public health concerns largely have disregarded the important overlap between eating disorders and obesity. This Special Issue addresses this neglect and points to how progress can be made in preventing and treating both. Thirteen primary research papers, three reviews, and two commentaries comprise this Special Issue. Two commentaries set the scene, noting the need for an integrated approach to prevention and treatment. The empirical papers and reviews fall into four broad areas of research: first, an understanding of the neuroscience of eating behaviours and body weight; second, relationships between disordered eating and obesity risk; third, new and integrated approaches in treatment; and fourth, assessment. Collectively, the papers highlight progress in science, translational research, and future research directions.