Cortical thickness, neurocognitive, and body composition effects of fasting during Ramadan

We aimed to study the anatomical, physiological, and cognitive function of healthy individuals practicing fasting during
the month of Ramadan. Measurements were taken 1 week before and 2 weeks after Ramadan fasting. Twelve
healthy male individuals (mean age ± standard error of the mean: 34.3 ± 2.9 years; body mass index: 26.26 ± 1.4 kg/m2) were assessed for
various parameters before and after Ramadan fasting. All the tests were performed in the morning. Body composition characteristics
were assessed by bioelectrical impedance analysis using a commercially available body composition analyzer. For neurocognitive
analysis, participants underwent the stop signal task (SST), pattern recognition memory task (PRM), and spatial working memory
strategy (SWM) from the Cambridge Neuropsychological Test Automated Battery. T1‑weighted, 1 mm‑thick magnetic resonance
images were also acquired. Anthropometric analysis showed a significant decrease in body weight, fat‑free mass (FFM),
trunk FFM, and trunk predicted muscle mass, while the other body composition parameters did not exhibit any changes. The stop
signal reaction time (SSRT) latency (ms) (P > 0.05) and PRM did not show any significant difference before and after fasting. SWM
task (P < 0.05) improved significantly after fasting. Cortical thickness data of the whole brain were not significantly different after
fasting at any brain location. There was a significant correlation between the left amygdala and the SWM strategy (r2 = 0.518) and
between fat and brain segmentation volume (r2 = 0.375). Our pilot data suggest that Ramadan fasting leads to weight
loss and FFM reductions and improve cognitive function.