A Ketone Ester Drink Lowers Human Ghrelin and Appetite.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 29105987 · doi:10.1002/oby.22051
What was done
Fifteen normal-weight subjects consumed either an exogenous ketone ester (KE; 1.9 kcal/kg) drink or an isocaloric dextrose (DEXT) drink matched for volume, taste, tonicity, and color after an overnight fast. Investigators measured blood levels of d-β-hydroxybutyrate (BHB), glucose, insulin, ghrelin, glucagon-like peptide 1 (GLP-1), and peptide tyrosine tyrosine (PYY), as well as visual analogue scale scores for hunger, fullness, and desire to eat.
What was found
KE increased blood BHB from 0.2 to 3.3 mM after 60 minutes, while DEXT increased plasma glucose between 30 and 60 minutes. Postprandial plasma insulin, ghrelin, GLP-1, and PYY were significantly lower 2 to 4 hours post-KE compared with DEXT. Reported hunger and desire to eat were significantly suppressed 1.5 hours after KE compared to DEXT. Specific numerical values for appetite scores and hormones were not provided in the abstract.
Why it matters
This trial suggests that acute elevation of blood ketones via exogenous ketone ester consumption directly suppresses the appetite-stimulating hormone ghrelin and subjective hunger sensations, independent of a sustained ketogenic diet.
Limits
The sample size was very small (n = 15) and limited to normal-weight participants. The study tested only an acute, single-dose response over a few hours and did not measure actual ad libitum food intake or long-term effects on body weight.