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

Abstract

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.

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

“…In a scientific context in which the link between EFs and obesity needs to be further investigated [ 7 , 25 , 51 , 52 , 53 , 54 , 81 ], our findings showed that morbidly obese individuals got poor executive scores regardless of the significant effects of the above-mentioned covariates. Notably, in line with previous studies [ 50 ], we found no significant differences between obese, overweight, and normal-weight subjects on the executive domains explored. This evidence suggests that severe obesity, more than obesity, may represent a clinical condition that impacts on cognition.…”

“…These findings are supported by neuroimaging studies showing hypoperfusion within frontal territories and the adjacent portions of temporal and parietal cortices in patients with a higher body mass index (BMI) [ 43 , 44 , 45 ]. However, some investigations have reported conflicting evidence suggesting that obese subjects would get, in line with the “obesity paradox” [ 46 , 47 ], equal or better performance than normal-weight subjects on executive tasks [ 24 , 48 , 49 , 50 ].…”

Physiological Role of Orexinergic System for Health

“…This includes the overconsumption of highly palatable food that is rich in fat and sugar in the absence of caloric need [ 102 , 106 , 107 ]. In fact, projections between the prefrontal area and hypothalamic circuits appear to be relevant for the modulation of hunger and satiety signals [ 108 , 109 ]. The preference for agreeable food is related to a significant increase in orexin gene expression in the perifornical area [ 110 ] and the double expression of orexin and Fos (a marker of neuronal activation) in the lateral hypothalamus [ 13 ].…”

The Role of Nutraceutical Supplements, Monacolin K and Astaxanthin, and Diet in Blood Cholesterol Homeostasis in Patients with Myopathy

“…Univariate outliers (i.e., z -scores = |3|) were removed. If needed, square root transformation (√X i ) was performed to normalize variables in line with skewness and kurtosis parameters (i.e., < |1|) [ 49 , 50 ]. For multivariate diagnostics of outliers, the Mahalanobis’ distance ( ) was calculated and Mardia’s coefficient was assessed.…”