Brain Functional Connectivity Is Modified by a Hypocaloric Mediterranean Diet and Physical Activity in Obese Women

Abstract

Functional magnetic resonance imaging (fMRI) in the resting state has shown altered brain connectivity networks in obese individuals. However, the impact of a Mediterranean diet on cerebral connectivity in obese patients when losing weight has not been previously explored. The aim of this study was to examine the connectivity between brain structures before and six months after following a hypocaloric Mediterranean diet and physical activity program in a group of sixteen obese women aged 46.31 ± 4.07 years. Before and after the intervention program, the body mass index (BMI) (kg/m2) was 38.15 ± 4.7 vs. 34.18 ± 4.5 (p < 0.02), and body weight (kg) was 98.5 ± 13.1 vs. 88.28 ± 12.2 (p < 0.03). All subjects underwent a pre- and post-intervention fMRI under fasting conditions. Functional connectivity was assessed using seed-based correlations. After the intervention, we found decreased connectivity between the left inferior parietal cortex and the right temporal cortex (p < 0.001), left posterior cingulate (p < 0.001), and right posterior cingulate (p < 0.03); decreased connectivity between the left superior frontal gyrus and the right temporal cortex (p < 0.01); decreased connectivity between the prefrontal cortex and the somatosensory cortex (p < 0.025); and decreased connectivity between the left and right posterior cingulate (p < 0.04). Results were considered significant at a voxel-wise threshold of p ≤ 0.05, and a cluster-level family-wise error correction for multiple comparisons of p ≤ 0.05. In conclusion, functional connectivity between brain structures involved in the pathophysiology of obesity (the inferior parietal lobe, posterior cingulate, temporo-insular cortex, prefrontal cortex) may be modified by a weight loss program including a Mediterranean diet and physical exercise.

Changes in brain activity after weight loss

“…However, one could also speculate that these alterations after weight loss might even drive food intake leading to regaining of weight after the diet has ended. Interestingly, the current findings are in line with a recent study showing alterations in the same brain areas (insula and frontal cortex) upon a weight loss intervention . This study did look at changes in functional connectivity instead of BOLD activity, which is a different measure of brain function, but the areas affected by the weight loss intervention are nonetheless very similar.…”

Obesity and Gray Matter Volume Assessed by Neuroimaging: A Systematic Review

“…In addition, a lower GMV was also found in the parietal and occipital cortex, cerebellum, insula, basal ganglia, thalamus, amygdala, limbic lobes and other regions [6][7][8][9]25,29,[42][43][44][45][46]48,50,57,59,[61][62][63][64]66]. Many of these areas have been shown to have decreased connectivity specifically in the parietal cortex, posterior cingulate and prefrontal cortex after a program with a Mediterranean diet and physical activity in obese people [67]. In addition, lower connectivity in the posterior cingulate and lateral inferior parietal posterior cingulate cortex, involved in the coordination of self-referential thinking and internal state subsystems such as appetite or other gut signal processing or food-related cognitive factors, was also reported in obese people [68].…”

A review of the relationship between eating behavior, obesity and functional brain network organization

“… García-Casares et al (2017) examined the effects of a 6 month weight loss intervention involving Mediterranean diet (a diet rich in ω-3FAs) and physical activity on functional connectivity in adult women with obesity. All individuals in the sample successfully lost weight during the intervention.…”