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 andabdominal fat accumulation, and mediating roles of circulating lipidomicsignatures. We quantified 1245 circulating lipids in 150 normal-weight centralobesity (NWCO) cases and 150 controls using targeted lipidomics. Grainpreference was determined by the highest intake frequency of grains (whiterice, wheat, or coarse grain). In our participants with high wheat intakefrequency, preferring coarse grain over rice was associated with a 60% lowerrisk of NWCO. Of the 585 lipids showing opposing associations with white riceand coarse grains, 46 were significantly linked to either (p < 0.05), predominantly alkylacyl phospholipids (PE-Os; n < 9) and alkenylacylphospholipids (PE-Ps; nx = 7). Network analysis identified a module primarilycomposed of PE-Os and PE-Ps, which was positively associated with coarse grain (p = 0.014). Another module, mainly consisting of triacylglycerols (TGs), was associatedwith 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 highwheat intake frequency, preferring coarse grain was inversely associated with NWCO, mediated by specific lipidomic signatures.