Altered immunometabolic response to fasting in humans living with obesity.

Fasting and ketosis are gaining interest for treating obesity-related immunometabolic dysfunction. We aimed to (1) characterize systemic and T cell immunometabolic responses to a 48-h fast in humans and (2) determine if responses differed between individuals with (O-BMI) and without (L-BMI) obesity (n = 16 per group). Despite similar increases in systemic fat oxidation, increases in blood β-hydroxybutyrate (BHB), BHB-amino acid conjugates, and lysine β-hydroxybutyrylation were blunted in obesity.