Body Fat and the Cognitive Pattern: a Population-Based Study

Objective: We investigated the relationship between body fatness and cognitive pattern at a population level. Design and Methods: Among 500 unselected subjects from general population, we analyzed the role of body mass index (BMI) and body fat mass (BFM) on mini mental state examination (MMSE) and on a battery of paper and pencil neuropsychological tests. Multiple linear regressions, accounting for potential confounders, were used. Results: In fully adjusted models, MMSE (coefficient +0.027, 95% confidence intervals, 0.017 to 0.177), the clock drawing test (+0.141, 0.053 to 0.226) and the trail making test A (+1.542, 0.478 to 2.607) were positively associated to BMI. Adding BFM to the models, no associations were observed. The tests were also positively associated to BFM (+0.056, 0.021 to 0.091; +0.063, 0.025 to 0.101; +0.592, 0.107 to 1.077; respectively). At analysis of covariance, the same tests were significantly better performed over 29.4 kg m-2 of BMI. Adding BFM as further confounder, all differences in performance across BMI became no more significant. The three tests were better performed over 34.6 kg of BFM. Conclusions: Higher BMI and particularly higher BFM are positively associated to better performance at the cognitive tasks exploring selective attention and executive functions.