Prior ingestion of exogenous ketone monoester attenuates the glycaemic response to an oral glucose tolerance test in healthy young individuals

In a randomized crossover study, 20 healthy participants (10 males and 10 females) aged 18 to 35 years consumed ketone monoester (0.45 ml per kg body weight) or water placebo 30 minutes before a 75 g oral glucose tolerance test after an overnight fast. The ketone monoester raised blood d-beta-hydroxybutyrate to 3.2 plus or minus 0.6 mM within 30 minutes, with levels remaining elevated throughout the test. Compared with placebo it reduced glucose area under the curve by 17 percent (P = 0.001), non-esterified fatty acid area under the curve by 44 percent (P < 0.001) and C-peptide incremental area under the curve (P = 0.005), and improved the oral glucose insulin sensitivity index by about 11 percent (P = 0.001).