Objectives This study aimed to assess the fatty acid (FA) composition of abdominal subcutaneous (ASAT) and visceral (VAT) adipose tissue in the UK Biobank imaging cohort (N = 33,823) using magnetic resonance imaging (MRI). Methods We measured the fractions of saturated (fSFA), monounsaturated (fMUFA), and polyunsaturated (fPUFA) in ASAT and VAT from multi-echo MRI scans. We selected a sub-cohort that followed a vegan and an omnivore diet (N=36) to validate the effect of diet on adipose tissue. In the wider imaging cohort, we examined the relationship between adipose tissue FA composition and various traits related to disease and body size. Results We measured adipose tissue FA composition for over 33,000 participants, revealing higher fSFA and fPUFA and lower fMUFA in VAT (p < 0.00016). fMUFA and fPUFA were higher in ASAT and lower in VAT for women (p<0.00016). Vegans exhibited lower fSFA in both ASAT and VAT (p < 0.00016). VAT fSFA and fMUFA showed significant associations with disease as well as anthropometric variables. Discussion This extensive analysis revealed the relationships between adipose tissue FA composition and a range of factors in a diverse population, highlighting the importance of studying body adipose tissue beyond its quantity. |