Serum Lipidomic Signatures Mediate the Association Between Coarse Grain Preference and Central Obesity in Adults With Normal Weight and High Wheat Intake

Little is known about the association between grain preference and abdominal fat accumulation, and mediating roles of circulating lipidomic signatures. We quantified 1245 circulating lipids in 150 normal-weight central obesity (NWCO) cases and 150 controls using targeted lipidomics. Grain preference was determined by the highest intake frequency of grains (white rice, wheat, or coarse grain). In our participants with high wheat intake frequency, preferring coarse grain over rice was associated with a 60% lower risk of NWCO. Of the 585 lipids showing opposing associations with white rice and coarse grains, 46 were significantly linked to either (p < 0.05), predominantly alkylacyl phospholipids (PE-Os; n = 9) and alkenylacylphospholipids (PE-Ps; n = 7). Network analysis identified a module primarily composed of PE-Os and PE-Ps, which was positively associated with coarse grain (p = 0.014). Another module, mainly consisting of triacylglycerols (TGs), was associated with white rice (p = 0.003) and mediated the association between white rice (mediation proportion: 20.30%; p = 0.027) or coarse grain preference (11.43%; p = 0.040) and NWCO. Specific lipids, such as TG(8:0_16:0_16:0) and TG(8:0_14:0_18:0), exhibited notable mediation effects. In normal-weight individuals with high wheat intake frequency, preferring coarse grain was inversely associated with NWCO, mediated by specific lipidomic signatures.