Research paper
Brennan IM, Luscombe-Marsh ND, Seimon RV, Otto B, Horowitz M, Wishart JM, Feinle-Bisset C. Effects of fat, protein, and carbohydrate and protein load on appetite, plasma cholecystokinin, peptide YY, and ghrelin, and energy intake in lean and obese men. American Journal of Physiology – Gastrointestinal and Liver Physiology. 2012;303(1):G129-140. doi:10.1152/ajpgi.00478.2011
Why we cite it
Demonstrates through a controlled crossover design that high-protein meals suppress subsequent energy intake in both lean and obese men, while revealing that obese individuals are specifically less sensitive to the satiating effects of fat — with sustained CCK and ghrelin responses to the protein meals, which the authors offer as a ”potentially mediated” route, bearing on why protein suppressed subsequent intake more than fat did in these participants. The paper’s own framing of the background ranking is worth keeping: ”While protein is regarded as the most satiating macronutrient, many studies have employed test meals that had very high and unsustainable protein contents.” (Hedge and framing added 2026-09-19.) (Previously: “why protein is the most satiating macronutrient” — a general ranking of the macronutrients, which this single crossover does not establish. Corrected 2026-09-02, card 6NM98H.)