Perseveration augments the effects of cognitive restraint on ad libitum food intake in adults seeking weight loss

Inhibition and shifting across the weight status spectrum

Executive functioning (EF) is of major interest in the study of cognitive factors involved in obesity. Among EF, shifting is related to behavioral flexibility, and inhibition to the ability to refrain from impulsive behavior. A deficit in those two EF could predict individual difficulties to maintain a healthy lifestyle. Weak evidence of deficits in shifting and inhibition in individuals of higher Body Mass Index (BMI) have been observed. The objective was to clarify the relationship between inhibition and shifting regarding weight status group differences in healthy adults. Two neuropsychological tests from the Test of Attentional Performance (TAP) battery were used to measure EF performance of three groups of men and women: normal-weight (NW, n = 38), overweight (OW, n = 40) and obesity (OB, n = 37). The results show that individuals with higher BMI have lower inhibition capacities and that classically used weight status categories might not capture cognitive variability. No differences in shifting were observed concerning weight status nor BMI. This paper provides new insights on cognitive factors in obesity by presenting data from healthy individuals with overweight and obesity. The results support that assessing inhibition capacities might be of interest in a clinical setting for patients with difficulties to lose weight.

Disinhibition augments thirst perception from two dehydrating stimuli in men

Physiological systems controlling water and energy ingestion are coordinated. Whether maladaptive eating behavior and appetite for water are linked is unknown. Thus, we sought to investigate the association between maladaptive eating and both thirst and water drinking behavior with two dehydrating conditions. Twenty-two lean men and 20 men with obesity (mean age 32.3 ± 8.4 years and 30.0 ± 11.1 years, respectively) completed the Three-Factor Eating Questionnaire (TFEQ) and Gormally Binge Eating Scale. On separate days, volunteers were dehydrated by a 2-h hypertonic saline infusion and a 24-h water deprivation, and thirst was measured on a 100-mm visual analogue scale (VAS) during each procedure. After each dehydrating condition, ad libitum water intake was measured. In the saline infusion, higher Disinhibition on the TFEQ was associated with thirst in the lean group (β = 4.2 mm VAS, p = 0.03) but not in the group with obesity (p = 0.51). In the water-deprivation condition, higher Disinhibition was also associated with thirst in the lean group (β = 5.6 mm VAS, p = 0.01) with the strength of relationship being 3.5-fold stronger than that observed in the group with obesity (β = 1.6 mm VAS, p = 0.0003). Hunger, Restraint, and binge-eating scores were not associated with thirst in either dehydrating condition (all p > 0.05). Maladaptive eating behaviors were not associated with ad libitum water intake (all p > 0.05). Disinhibition is associated with higher thirst perception in healthy weight individuals and may be attenuated in obesity. The characteristics of disinhibition which typically includes a heightened readiness to eat, may reflect a more general phenotype that also reflects a readiness to drink.

Exploratory analysis of eating- and physical activity-related outcomes from a randomized controlled trial for weight loss maintenance with exercise and liraglutide single or combination treatment

Weight regain after weight loss remains a major challenge in obesity treatment and may involve alteration of eating and sedentary behavior after weight loss. In this randomized, controlled, double-blind trial, adults with obesity were randomized, in a 1:1:1:1 ratio stratified by sex and age group (<40 years and ≥40 years), to one-year weight loss maintenance with exercise, the GLP-1 receptor agonist liraglutide, or the combination, as compared with placebo, after low-calorie diet-induced weight loss. Primary outcome was change in body weight, which has been published. Here, we investigated the effects of weight loss maintenance with exercise, liraglutide, or the combination on weight loss-induced changes in the pre-specified explorative outcomes, eating and sedentary behavior in 130 participants who completed the trial according to the study protocol (exercise (n = 26), liraglutide (n = 36), combination (n = 29), and placebo (n = 39)). One year after weight loss, the placebo group had decreased postprandial appetite suppression score by 14%, and increased sedentary time by 31 min/day and regained weight. Liraglutide prevented the decrease in postprandial appetite suppression score compared with placebo (0% vs. -14%; P = 0.023) and maintained weight loss. Exercise after weight loss did not increase appetite or sedentary behavior compared with placebo, despite increased exercise energy expenditure and maintained weight loss. The combination of exercise and liraglutide increased cognitive restraint score (13% vs. -9%; P = 0.042), reflecting a conscious restriction of food intake, and decreased sedentary time by 41 min/day (-10 vs. 31 min/day; 95%CI, -82.3 to -0.2; P = 0.049) compared with placebo, which may have facilitated the additional weight loss. Targeting both eating and sedentary behavior could be the most effective for preventing weight regain.Trial registration: EudraCT number, 2015-005585-32; clinicaltrials.gov number, NCT04122716.

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.

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

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

Childhood Obesity, Cortical Structure, and Executive Function in Healthy Children

The development of executive function is linked to maturation of prefrontal cortex (PFC) in childhood. Childhood obesity has been associated with changes in brain structure, particularly in PFC, as well as deficits in executive functions. We aimed to determine whether differences in cortical structure mediate the relationship between executive function and childhood obesity. We analyzed MR-derived measures of cortical thickness for 2700 children between the ages of 9 and 11 years, recruited as part of the NIH Adolescent Brain and Cognitive Development (ABCD) study. We related our findings to measures of executive function and body mass index (BMI). In our analysis, increased BMI was associated with significantly reduced mean cortical thickness, as well as specific bilateral reduced cortical thickness in prefrontal cortical regions. This relationship remained after accounting for age, sex, race, parental education, household income, birth-weight, and in-scanner motion. Increased BMI was also associated with lower executive function. Reduced thickness in the rostral medial and superior frontal cortex, the inferior frontal gyrus, and the lateral orbitofrontal cortex partially accounted for reductions in executive function. These results suggest that childhood obesity is associated with compromised executive function. This relationship may be partly explained by BMI-associated reduced cortical thickness in the PFC.

Food craving predicts the consumption of highly palatable food but not bland food

The impact of obesity on physical and psychological health is well recognized in the literature with, among others, evidence of alterations in cognition. Indeed, obese populations are characterized by lower executive functions as well as an enhanced food craving. However, the relationship between executive functions and food craving remains unexplored. Moreover, these two variables have also been shown to predict food intake, but studies in the context of obesity are lacking. Thus, this study had two objectives: (1) determining if executive functions and food craving are linked, and (2) examining the predictors of highly palatable food intake and bland food intake. First, it was hypothesized that executive functions would be negatively associated with food craving. Second, it was expected that food craving would predict positively highly palatable food intake but not bland food intake. Third, it was predicted that executive functions would predict negatively highly palatable food intake and positively bland food intake. 48 participants (34 females) with BMIs ranging from 17.9 to 46.4 took part in two experimental sessions. First, executive functions were assessed using the delayed discounting task (impulsivity towards food and money) and the color-word interference test (CWIT; inhibition/flexibility). Second, a cue-induced food craving protocol, with images as well as real food, was administered followed by an ad libitum food intake protocol including both highly palatable and bland food. The inhibition/flexibility condition of the CWIT was significantly and negatively correlated with food craving following induction. Highly palatable food intake was significantly predicted by food craving following induction, but bland food intake was not. This study reveals an association between lower inhibition/flexibility and susceptibility to food craving induction that is of great importance in obesogenic environments. Moreover, this study confirmed the link between food craving and food intake, and showed for the first time a specific contribution of food craving to highly palatable food intake but not to bland food intake, highlighting its potential influence in obesity. This work leads to future research questions regarding the possible benefits of cognitive remediation interventions, as well as interventions aiming at reducing food craving, in weight loss programs. LEVEL OF EVIDENCE: Level IV, quasi-experimental study.

Cognitive dietary restraint, disinhibition, and hunger are associated with 24-h energy expenditure

Background:

Higher energy expenditure (EE) is associated with greater food intake, possibly because the human body senses EE and modifies eating behaviors to regulate food intake and ultimately achieve energy balance. As eating behaviors are also influenced by social and cultural factors, any association between EE and eating behavior may differ between ethnicities and sexes.

Objective:

To assess relationships between EE and eating behavior constructs of the Three-Factor Eating Questionnaire (TFEQ).

Subjects/Methods:

307 healthy adults (201M/106F, 160 Native Americans) completed the TFEQ and had measures of 24-h EE in a whole-room calorimeter during energy balance. Body composition was assessed by DXA.

Results:

On average, adjusted 24-h EE was lower (β=−229 kcal/day, CI: −309-−148, p<0.001) but cognitive restraint (Δ=+1.5; CI: 0.5–2.5, p=0.003) and disinhibition (Δ=+2.1, CI: 1.3–2.8, p<0.001) scores were higher in women compared to men. In Native Americans, adjusted 24-h EE (β=+94 kcal/day, CI: 48–139, p<0.001) and disinhibition scores (Δ=+1.0, CI: 0.1–2.0, p=0.003) were higher compared to other ethnicities. Higher 24-h EE associated with lower cognitive restraint in women (ρ=−0.20, p=0.04), but not men (p=0.71; interaction term p=0.01) with no ethnic differences. Greater 24-h EE associated with higher disinhibition (ρ=0.20, p=0.001) and hunger cues (ρ=0.16, p=0.004) with no gender differences. These associations were primarily present in non-Native Americans (ρ=0.23, p=0.006 and ρ=0.25, p=0.003) but not observed in Native Americans (both p>0.40).

Conclusions:

Higher EE is associated with psychological constructs of eating behaviors that favors overeating including lower cognitive restraint, higher dietary disinhibition, and greater susceptibility to hungers cues, supporting the existence of energy-sensing mechanisms influencing human eating behavior. These associations were observed in ethnicities other than Native Americans, possibly explaining the contradictory relationships reported between EE and weight change in different ethnic groups. We propose that increased EE may alter eating behaviors, potentially leading to uncontrolled overeating and weight gain.

Validation of a child version of the Three-Factor Eating Questionnaire in a Canadian sample: a psychometric tool for the evaluation of eating behaviour

OBJECTIVE

To examine score validity and reliability of a child version of the twenty-one-item Three-Factor Eating Questionnaire (CTFEQ-R21) in a sample of Canadian children and adolescents and its relationship with BMI Z-score and food/taste preferences.

DESIGN

Cross-sectional study.

SETTING

School-based.

PARTICIPANTS

Children (n 158), sixty-three boys (mean age 11·5 (sd 1·6) years) and ninety-five girls (11·9 (sd 1·9) years).

RESULTS

Exploratory factor analysis revealed that the CTFEQ-R21 was best represented by four factors with item 17 removed (CFFEQ-R20), representing Cognitive Restraint (CR), Cognitive Uncontrolled Eating (UE 1), External Uncontrolled Eating (UE 2) and Emotional Eating (EE), accounting for 41·2 % of the total common variance with good scale reliability. ANOVA revealed that younger children reported higher UE 1 and CR scores than older children, and boys who reported high UE 1 scores had significantly higher BMI Z-scores. Children with high UE 1 scores reported a greater preference for high-protein and -fat foods, and high-fat savoury (HFSA) and high-fat sweet (HFSW) foods. Higher preference for high-protein, -fat and -carbohydrate foods, and HFSA, HFSW and low-fat savoury foods was found in children with high UE 2 scores.

CONCLUSIONS

The study suggests that the CFFEQ-R20 can be used to measure eating behaviour traits and associations with BMI Z-score and food/taste preferences in Canadian children and adolescents. Future research is needed to examine the validity of the questionnaire in larger samples and other geographical locations, as well as the inclusion of extraneous variables such as parental eating or socio-economic status.

Development and validation of the Child Three-Factor Eating Questionnaire (CTFEQr17)

OBJECTIVE

To develop and validate a child and adolescent version of the Three-Factor Eating Questionnaire (CTFEQr17) and to assess its psychometric properties and factor structure. We also examined associations between the CTFEQr17 and BMI and food preferences.

DESIGN

A two-phase approach was utilized, employing both qualitative and quantitative methodologies.

SETTING

Primary and secondary schools, UK.

SUBJECTS

In phase 1, seventy-six children (thirty-nine boys; mean age 12·3 (sd 1·4) years) were interviewed to ascertain their understanding of the original TFEQr21 and to develop accessible and understandable items to create the CTFEQr17. In phase 2, 433 children (230 boys; mean age 12·0 (sd 1·7) years) completed the CTFEQr17 and a food preference questionnaire, a sub-sample (n 253; 131 boys) had their height and weight measured, and forty-five children (twenty-three boys) were interviewed to determine their understanding of the CTFEQr17.

RESULTS

The CTFEQr17 showed good internal consistency (Cronbach's α=0·85) and the three-factor structure was retained: cognitive restraint (CR), uncontrolled eating (UE) and emotional eating (EE). Qualitative data demonstrated a high level of understanding of the questionnaire (95 %). High CR was found to be significantly associated with a higher body weight, BMI and BMI percentile. High UE and EE scores were related to a preference for high-fat savoury and high-fat sweet foods. The relationships between CTFEQr17, anthropometry and food preferences were stronger for girls than boys.

CONCLUSIONS

The CTFEQr17 is a psychometrically sound questionnaire for use in children and adolescents, and associated with anthropometric and food preference measures.

Depressive symptoms and poorer performance on the Stroop Task are associated with weight gain

OBJECTIVE

Executive function impairments and depression are associated with obesity but whether they predict weight gain is unclear.

METHODS

Forty-six individuals (35m, 37±10y) completed the Stroop Task, Iowa Gambling Task (IGT), Wisconsin Card Sorting Task (WCST), Inventory for Depressive Symptomatology (IDS-SR), Physical Anhedonia Scale (PAS), and Perceived Stress Scale (PSS). Body composition (DXA) and fasting glucose were also measured. Data from return visits were used to assess changes in weight.

RESULTS

Poorer Stroop and WCST performance associated with higher BMI whereas poorer IGT and WCST performance associated with higher body fat (%; all p's≤0.05). Stroop interference (p=0.04; p=0.05) and IDS-SR (p=0.06; p=0.02) associated with increased BMI and weight gain (%/yr). In a multivariate linear model Stroop interference (β=0.40, p<0.01; β=0.35, p<0.01) and IDS-SR (β=0.38, p<0.01; β=0.37, p<0.01) independently predicted increased BMI and weight gain (%/yr) even after controlling for baseline weight and glucose levels.

CONCLUSIONS

Poorer response inhibition and depressive symptoms, but not glucose levels, predicted weight gain. Evaluating neurocognitive and mood deficits could improve current treatment strategies for weight loss. Clinical Trial Registration Numbers NCT00523627, NCT00342732, NCT01224704. clinicaltrials.gov.

Obesity, Appetite, and the Prefrontal Cortex

PURPOSE OF REVIEW

Obesity is a chronic illness and its prevalence is growing worldwide and numerous factors play a role in the regulation of food intake. The prefrontal cortex (PFC) is involved in high-order executive function, regulation of limbic reward regions, and the inhibition of impulsive behaviors. Understanding the role of the PFC in the control of appetite regulation may contribute to a greater understanding of the etiology of obesity and could improve weight loss outcomes.

RECENT FINDINGS

Neuroimaging studies have identified lower activation in the left dorsolateral PFC (DLPFC) in obese compared to lean individuals and others have focused on efforts to improve cognitive control in this area of the brain. The DLPFC is a critical brain area associated with appetitive control, food craving, and executive functioning, indicating a candidate target area for treatment. Further studies are needed to advance our understanding of the relationship between obesity, appetite, and the DLPFC and provide validation for the effectiveness of novel treatments in clinical populations.

Discussing the putative role of obesity-associated genes in the etiopathogenesis of eating disorders

In addition to the identification of mutations clearly related to Mendelian forms of obesity; genome-wide association studies and follow-up studies have in the last years pinpointed several loci associated with BMI. These genetic alterations are located in or near genes expressed in the hypothalamus that are involved in the regulation of eating behavior. Accordingly, it seems plausible that these SNPs, or others located in related genes, could also help develop aberrant conduct patterns that favor the establishment of eating disorders should other susceptibility factors or personality dimensions be present. However, and somewhat surprisingly, with few exceptions such as BDNF, the great majority of the genes governing these pathways remain untested in patients with anorexia nervosa, bulimia nervosa or binge-eating disorder. In the present work, we review the few existing studies, but also indications and biological concepts that point to these genes in the CNS as good candidates for association studies with eating disorder patients.