Trait impulsivity and body mass index: A cross-sectional investigation in 3073 individuals reveals positive, but very small relationships

Relation of BOLD response to food-specific and generic motor response inhibition tasks to body fat gain in adults with overweight and obesity

BACKGROUND

Low inhibitory control has been theorized to contribute to the development and maintenance of obesity. Knowledge on the neurobiological indicators of inhibitory control deficits predicting future weight gain is limited. The current study examined if individual differences in blood-oxygenation-level-dependent (BOLD) activity associated with food-specific and general motor response inhibition predict future body fat change in adults with overweight or obesity.

METHODS

BOLD activity and behavioral responses of adults with overweight or obesity (N = 160) were recorded while performing a food-specific stop signal task (n = 92) or a generic stop signal task (n = 68). Percent body fat was measured at baseline, posttest, 3-month, and 6-month follow-up.

RESULTS

Elevated BOLD activity in somatosensory (postcentral gyrus), and attention (precuneus) regions during successful inhibition in the food-specific stop signal task and elevated BOLD activity in a motor region (anterior cerebellar lobe) in the generic stop signal task predicted greater body fat gain over 6-month follow-up. Elevated BOLD activity in inhibitory control regions (inferior-, middle-, superior frontal gyri) and error monitoring regions (anterior cingulate cortex, insula) during erroneous responses in the generic stop signal task predicted body fat loss.

CONCLUSIONS

Results suggest that improving motor response inhibition and error monitoring may facilitate weight loss in adults with overweight and obesity.

Neuro-Vulnerability in Energy Metabolism Regulation: A Comprehensive Narrative Review

This comprehensive narrative review explores the concept of neuro-vulnerability in energy metabolism regulation and its implications for metabolic disorders. The review highlights the complex interactions among the neural, hormonal, and metabolic pathways involved in the regulation of energy metabolism. The key topics discussed include the role of organs, hormones, and neural circuits in maintaining metabolic balance. The review investigates the association between neuro-vulnerability and metabolic disorders, such as obesity, insulin resistance, and eating disorders, considering genetic, epigenetic, and environmental factors that influence neuro-vulnerability and subsequent metabolic dysregulation. Neuroendocrine interactions and the neural regulation of food intake and energy expenditure are examined, with a focus on the impact of neuro-vulnerability on appetite dysregulation and altered energy expenditure. The role of neuroinflammation in metabolic health and neuro-vulnerability is discussed, emphasizing the bidirectional relationship between metabolic dysregulation and neuroinflammatory processes. This review also evaluates the use of neuroimaging techniques in studying neuro-vulnerability and their potential applications in clinical settings. Furthermore, the association between neuro-vulnerability and eating disorders, as well as its contribution to obesity, is examined. Potential therapeutic interventions targeting neuro-vulnerability, including pharmacological treatments and lifestyle modifications, are reviewed. In conclusion, understanding the concept of neuro-vulnerability in energy metabolism regulation is crucial for addressing metabolic disorders. This review provides valuable insights into the underlying neurobiological mechanisms and their implications for metabolic health. Targeting neuro-vulnerability holds promise for developing innovative strategies in the prevention and treatment of metabolic disorders, ultimately improving metabolic health outcomes.

Gender differences in the pathway of childhood trauma, impulsivity and adult eating behaviour: a cross-sectional study

Objective: The current cross-sectional study aimed to examine the association between childhood trauma, impulsivity, binge eating symptoms, and body mass index (BMI) in a sample of males and females. We also aimed to investigate the indirect association of childhood trauma with binge eating through impulsivity while controlling for BMI.Method: Participants were 410 young adults (mean age = 20.9 years, range 18-24; female = 73.9%) who completed online measures of childhood trauma, impulsivity, binge eating symptoms, and self-reported height and weight. Mediation models were tested using multi-group structural equation modelling.Results: Childhood trauma and impulsivity were associated with an increased risk of binge eating symptoms in females but not males, corroborating previous studies. There was a significant difference in the binge eating symptoms index between sexes, but not regarding the index of childhood trauma and impulsivity. Additionally, adverse childhood experiences were associated with impulsivity and the association of childhood trauma with binge eating was mediated by impulsivity in the female sample.Conclusions: Our results suggest sex-dependent patterns and risk factors that may impact binge eating symptoms. The implications of our results suggest that impulsivity might be a vulnerability factor for binge eating, especially for females.

Impulsive Personality Traits Predicted Weight Loss in Individuals with Type 2 Diabetes after 3 Years of Lifestyle Interventions

Impulsivity has been associated with type 2 diabetes (T2D) and may negatively impact its management. This study aimed to investigate impulsive personality traits in an older adult population with T2D and their predicting role in long-term weight control and glycemic management, through glycated hemoglobin (HbA_1c), following 3 years of intervention with a Mediterranean diet. The Impulsive Behavior Scale (UPPS-P) was administered as a measure of impulsive traits at baseline. Results showed higher total baseline scores of UPPS-P, and higher positive urgency in individuals with T2D, compared with those without T2D. The regression analysis in patients with T2D showed that sensation seeking and lack of perseverance predicted weight loss at follow-up. By contrast, impulsive traits did not predict follow-up levels of HbA_1c. In conclusion, the present findings suggest that higher impulsive traits in individuals with T2D seem to affect long-term weight control, but not glycemic control.

How Impulsiveness Influences Obesity: The Mediating Effect of Resting-State Brain Activity in the dlPFC

Impulsiveness is a stable personal characteristic that contributes to obesity and may interact with it. Specifically, obesity is caused by unrestrained impulse eating that is not consciously controlled and leads to a hormonal imbalance that also can impair impulse control. However, the mechanism of this relationship is unclear. In our study, 35 obese individuals (body mass index, BMI > 28) were recruited and matched with 31 healthy controls (BMI < 24) in age and education level. All the participants underwent a resting-state fMRI and completed the Barratt Impulsiveness Scale-11. The results showed that patients with obesity had a significantly lower fractional amplitude of low-frequency fluctuations (fALFF) in the bilateral dorsolateral prefrontal cortex (dlPFC) and higher fALFF in the left fusiform cortex. In addition, non-planning impulsiveness was positively correlated with BMI. Importantly, we found that the right dlPFC completely mediated the relationship between non-planning impulsiveness and BMI. Our findings suggest that impulsivity is statistically more likely to precede obesity than to precede impulsivity and contributes to obesity by downregulating spontaneous activity in the dlPFC. This suggests that the dlPFC, which is associated with executive control, may be able a potential target for treating obesity.

Patterns of weight loss and their determinants in a sample of adults with overweight and obesity intending to lose weight

AIM

Weight loss success is highly variable among individuals. Cluster analysis contributes to future intervention development by recognising this individual variability and identifying different weight loss patterns. Identifying determinants that differentiate between these patterns would explain the source of variability. Thus, we aimed to identify weight loss patterns and their determinants in adults with overweight and obesity.

METHODS

The present study is a secondary analysis of data from the PortionControl@HOME study. The weight of 175 adults was measured at 0, 3 and 12 months and potential determinants were self-reported using validated questionnaires at 0 and 3 months. Weight loss patterns were identified based on percent weight change during Phase 1 (0-3 months) and Phase 2 (3-12 months) using cluster analysis. Determinants were assessed using multinomial logistic regression.

RESULTS

We identified three weight loss patterns: (i) low success, demonstrating low weight loss achievement, (ii) moderate success, demonstrating successful weight loss in Phase 1 followed by partial regain in Phase 2 and (iii) high success, demonstrating weight loss in Phase 1 followed by continued weight loss in Phase 2. Compared to the moderate success pattern, the low success pattern was negatively associated with power of food at baseline (i.e. the appetitive drive to consume highly palatable food) (odds ratio, OR = 0.42, 95% CI = 0.21-0.86) and change in portion control behaviour (i.e. the use of behavioural strategies to control the amount of food consumed) (OR = 0.28, 95% CI = 0.10-0.78).

CONCLUSIONS

Three weight loss patterns were identified in adults with overweight and obesity. Adults with greater power of food and increased portion control behaviour were less likely to exhibit an unsuccessful weight loss pattern.

Body weight and its association with impulsivity in middle and old age individuals

Impulsivity, conceptualized as impulsive personality trait, poor inhibitory control and enhanced reward sensitivity, has been strongly linked to obesity. In particular, a disequilibrium between cognitive control and reward sensitivity has been observed in obese individuals in both behavioural and imaging studies. While this issue has been widely investigated in children and adults, it has received little attention in older adults. Here, obese and non-obese participants aged between 40 and 70 years completed the Barratt Impulsiveness scale (assessing motor, non-planning and attentional impulsiveness), a Go/no-go task with foods and non-foods (assessing inhibitory control) and a reward sensitivity battery with high and low caloric foods (assessing liking, wanting, tastiness and frequency of consumption). We observed that participants with higher BMI reported increased wanting for high calorie foods, but did not show poorer inhibitory control. Interestingly, participants who scored lower on the MMSE reported to consume high calorie more than low calorie foods. Finally, those who presented low scores on non-planning and motor impulsiveness subscales reported higher tastiness ratings for low calorie foods. These results show that increased reward sensitivity but not reduced inhibitory control may characterize higher BMI during aging. Importantly, they also highlight new findings concerning food preferences among older adults.

The Impact of Self-Reported Impulsivity on the Course of Weight Is Mediated by Disinhibited Eating

This study investigates the impact of impulsivity and the mediating role of disinhibited eating behaviour (DEB) on weight and weight trajectories in a large data set including obese non-treatment seeking individuals (obese control, n = 138) and obese individuals who were either receiving a conventional treatment program (n = 227) or bariatric surgery (n = 123). Data was assessed one, 4 and 9 years after baseline including self-reports for impulsivity and DEB. Results suggest a significant association between impulsivity and body mass index, which is partially mediated by DEB. Longitudinally, the influence of impulsivity on the course of weight after 9 years was fully mediated by DEB in obese control but not in the treatment groups. The results indicate an interplay between impulsivity and DEB with respect to obesity. Further research is needed to clarify how the mediation works and when it exerts its effect, in order to identify those that might profit from a specific (impulsivity-reducing) training. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Interactive and indirect effects of trait impulsivity facets on body mass index

Impulsivity is a personality trait that may be a risk factor for overweight and obesity. Increasing evidence suggests, however, that only specific facets of impulsivity are associated with eating- and weight-related variables. Moreover, there seem to be interactive effects such that eating-related self-regulation is low when more than one impulsivity facet is elevated. Finally, the effect of impulsivity on body weight appears to be indirect, that is, is mediated by eating behaviors. In the current study, 790 adults (83% female, 80% students) completed a short form of the Barratt Impulsiveness Scale and the Perceived Self-Regulatory Success in Dieting Scale online and reported their current height and weight. Scores on attentional and motor impulsivity were interactively associated with perceived self-regulatory success in weight regulation: Higher attentional impulsivity was associated with lower perceived self-regulatory success at high levels of motor impulsivity, but not at low levels of motor impulsivity. A moderated mediation model revealed an indirect effect of attentional impulsivity on body mass index (BMI) via perceived self-regulatory success in weight regulation at high, but not low levels of motor impulsivity. Non-planning impulsivity was unrelated to perceived self-regulatory success in weight regulation and BMI. Results support previous findings such that attentional and motor impulsivity are interactively associated with eating- and weight-related measures. Specifically, eating-related self-regulation is low when both attentional and motor impulsivity levels are high. Moreover, results further support that self-reported trait impulsivity is not directly related to BMI, but indirectly via eating behaviors as potential mediators.

Indirect effects of trait impulsivity on body mass

Trait impulsivity has been suggested as a risk factor for weight gain. However, it is implausible that a construct that does not cover energy intake or expenditure affects fat mass directly. Instead, it is likely that eating-related variables mediate the effect of impulsivity on body mass. In the current study, a serial mediation model tested two eating-related variables (trait food craving and perceived self-regulatory success in weight regulation) as mediators of the relationship between trait impulsivity and body mass. Participants (n=432, 88% female, 79% students) completed the Barratt Impulsiveness Scale - short form, the Food Cravings Questionnaire-Trait-reduced, and the Perceived Self-Regulatory Success in Dieting Scale (PSRS), in addition to providing sociodemographic and anthropometric data. Trait impulsivity did not correlate with body mass index (BMI), but was indirectly related to BMI via food cravings and PSRS scores. Specifically, higher impulsivity predicted more frequent food cravings, which in turn predicted lower perceived self-regulatory success in eating and weight regulation, which in turn predicted higher BMI. Findings suggest possible mechanisms that mediate the association between impulsivity and BMI. Importantly, they show that impulsivity can indirectly affect BMI via eating-related variables, even in the absence of a total effect. Longitudinal studies are needed that support these assumed causal directions.

Overlapping Neural Endophenotypes in Addiction and Obesity

Impulsivity refers to a tendency to act rapidly without full consideration of consequences. The trait is thought to result from the interaction between high arousal responses to potential rewards and poor self-control. Studies have suggested that impulsivity confers vulnerability to both addiction and obesity. However, results in this area are unclear, perhaps due to the high phenotypic complexity of addictions and obesity. Focusing on impulsivity, the aim of this review is to tackle the putative overlaps between addiction and obesity in four domains: (1) personality research, (2) neurocognitive tasks, (3) brain imaging, and (4) clinical evidence. We suggest that three impulsivity-related domains are particularly relevant for our understanding of similarities between addiction and obesity: lower self-control (high Disinhibition/low Conscientiousness), reward sensitivity (high Extraversion/Positive Emotionality), and negative affect (high Neuroticism/Negative Emotionality). Neurocognitive studies have shown that obesity and addiction are both associated with increased impulsive decision-making and attention bias in response to drug or food cues, respectively. Mirroring this, obesity and different forms of addiction seem to exhibit similar alterations in functional MRI brain activity in response to reward processing and during self-control tasks. Overall, our review provides an integrative approach to understand those facets of obesity that present similarities to addictive behaviors. In addition, we suggest that therapeutic interventions targeting inhibitory control may represent a promising approach for the prevention and/or treatment of obesity.