Personality and Body Weight: Mechanisms, Longitudinal Associations and Context

A bottom-up approach dramatically increases the predictability of body mass from personality traits

Personality traits consistently relate to and allow predicting body mass index (BMI), but these associations may not be adequately captured with existing inventories' domains or facets. Here, we aimed to test the limits of how accurately BMI can be predicted from and described with personality traits. We used three large datasets (combined N ≈ 100,000) with nearly 700 personality assessment items to (a) empirically identify clusters of personality traits linked to BMI and (b) identify relatively small sets of items that predict BMI as accurately as possible. Factor analysis revealed 14 trait clusters showing well-established personality trait-BMI associations (disorganization, anger) and lesser-known or novel ones (altruism, obedience). Most of items' predictive accuracy (up to r = .24 here but plausibly much higher) was captured by relatively few items. Brief scales that predict BMI have potential clinical applications-for instance, screening for risk of excessive weight gain or related complications.

Body mass predicts personality development across 18 years in middle to older adulthood

OBJECTIVE

Various personality traits have longitudinal relations with body mass index (BMI), a measure of body weight and a risk factor for numerous health concerns. We tested these associations' compatibility with causality in either direction.

METHOD

Using three waves of the Wisconsin Longitudinal Study (N = 12,235, Mage  = 53.33 at baseline), we tested how accurately the Five-Factor Model personality domains and their items could collectively predict BMI and change in it with elastic net models. With multilevel models, we tested (a) bidirectional and (b) within-person associations between BMI and personality traits.

RESULTS

The five domains were able to predict concurrent (r = 0.08), but not future BMI. Twenty-nine personality items predicted concurrent and future BMI at r = 0.21 and r = 0.16 to 0.25, respectively. Neither the domains nor items could collectively predict change in BMI. Similarly, no individual trait predicted change in BMI, but BMI predicted changes in Conscientiousness, Agreeableness, and several items (|b*| = 0.03 to 0.08). BMI had within-person correlations with these same traits; time-invariant third factors like genetics or childhood environments therefore could not (fully) account for their relations.

CONCLUSIONS

Body weight may contribute to adults' personality development, but the reverse appears less likely.

Personality, negative affectivity and emotional intelligence: gender-differentiated relationships with physical exercise

Introduction

Physical exercise is one of the most relevant lifestyle choices for the prevention of diseases; however, participation in this type of activity remains low. Therefore, it is necessary to deepen the understanding of related psychological factors in men and women.

Objective

To determine whether personality traits, emotional intelligence and negative affective are differentially related to physical exercise characteristics in men and women.

Method

A cross-sectional study was conducted with 579 physically active people (61.1% men) between 18 and 59 years of age. The Big Five Inventory (BFI-15p), Brief Emotional Intelligence Scale (EQ-i-M20), and Depression, Anxiety and Stress Scale (DASS-21) were used.

Results

Compared with men, women exercised fewer days and minutes per week, had fewer years of participation and performed fewer different physical exercises. On the emotional intelligence scale, compared with men, women showed less stress management, adaptability and general mood but greater interpersonal intelligence. With regard to personality traits, compared with men, women showed greater openness, conscientiousness, agreeableness, and neuroticism. In males, heightened levels of general mood and extraversion were associated to a lasting commitment to physical exercise over time. Conversely, in females, depression was negatively associated with the years dedicated to physical exercise.

Conclusion

Distinct approaches are essential for men and women, acknowledging the varied ways psychological factors are linked to physical exercise based on gender.

Conscientiousness is associated with less amyloid deposition in cognitively normal aging

Little is known about the association between personality and Alzheimer's disease (AD) biomarkers, and existing results are inconsistent. We aimed to determine whether personality was associated with β-amyloid (Aβ) accumulation in cognitively normal aging. One hundred twenty-nine participants were included in this cross-sectional study. Personality was measured with the Big Five Inventory (BFI) and brain Aβ deposition was assessed with [11C] Pittsburgh compound B (PiB)-positron emission tomography (PET) imaging. Conscientiousness scores had a negative association with global PiB distribution volume ratio (DVR) in all participants after adjusting for age, sex, education, and vascular risk factors (β[SE] = -0.19[0.09], 95% confidence interval [CI: -0.35, -0.02], p = .031), while agreeableness, extraversion, neuroticism, and openness had no association with global PiB DVR. Assuming the relative stability of personality traits, these findings suggest that conscientiousness may protect against Aβ accumulation in cognitively normal aging through mechanisms that are as yet unknown. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Personality, Chrono-nutrition and Cardiometabolic Health: A Narrative Review of the Evidence

Growing evidence suggests that personality traits play a role in obesity and cardiometabolic health. In addition, irregularity of food intake has emerged as a potential risk factor for obesity, cardiovascular disease, and metabolic syndrome. Recent studies suggest that when we eat, termed "chrono-nutrition," may be as important to what we eat. This concept covers 3 aspects: 1) irregularity of energy intake in meals (varying amounts of energy intake throughout the day and at different times from one day to the next), 2) frequency (number of meals per day), and 3) timing of food intake (actual time of day). A narrative review was conducted to identify literature evaluating the effect of personality on chrono-nutrition and subsequently obesity and cardiometabolic health. The search focused on research published since 2000 in MEDLINE using the search terms "personality," "chrono-nutrition," "cardiometabolic," "BMI," "obesity," and "metabolic rate." Findings indicate an inverse relation between conscientiousness and obesity, with people who are more conscientious having a lower risk of obesity. Furthermore, time of day of energy intake has been linked to obesity, since meals consumed in the evening have been associated with lower resting metabolic rate. Inconsistent timing and frequency of meals have also been linked to increased body weight and worse cardiometabolic health. Together, the data indicate that eating meals at the same time every day at regular intervals might be the reason why those who score high in conscientiousness are able to maintain a healthier weight. Despite the reviewed observational evidence, there is an apparent gap in the existing literature on the interplay between personality, chrono-nutrition, and obesity and particularly on how dietary interventions should be designed considering different personality traits. Future research is needed to clarify this association and how it interacts with other factors, thus elucidating the role of chrono-nutrition in health.

Personality-obesity associations are driven by narrow traits: A meta-analysis

Obesity has inconsistent associations with broad personality domains, possibly because the links pertain to only some facets of these domains. Collating published and unpublished studies (N = 14 848), we meta-analysed the associations between body mass index (BMI) and Five-Factor Model personality domains as well as 30 Five-Factor Model personality facets. At the domain level, BMI had a positive association with Neuroticism and a negative association with Conscientiousness domains. At the facet level, we found associations between BMI and 15 facets from all five personality domains, with only some Neuroticism and Conscientiousness facets among them. Certain personality-BMI associations were moderated by sample properties, such as proportions of women or participants with obesity; these moderation effects were replicated in the individual-level analysis. Finally, facet-based personality "risk" scores accounted for 2.3% of variance in BMI in a separate sample of individuals (N = 3569), 409% more than domain-based scores. Taken together, personality-BMI associations are facet specific, and delineating them may help to explain obesity-related behaviours and inform intervention designs. Preprint and data are available at https://psyarxiv.com/z35vn/.