The present study compared the effects of a high- and normal-casein-protein breakfast on satiety, 'satiety' hormones, plasma amino acid responses and subsequent energy intake. Twenty-five healthy subjects (BMI 23.9 (sem 0.3) kg/m2; age 22 (sem 1) years) received a subject-specific standardised breakfast (20 % of daily energy requirements): a custard with casein as the single protein source with either 10, 55 and 35 (normal-casein breakfast) or 25, 55 and 20 (high-casein breakfast) % of energy (En%) from protein, carbohydrate and fat respectively in a randomised, single-blind design. Appetite profile (visual analogue scale; VAS), plasma glucose, insulin, glucagon-like peptide 1, ghrelin and amino acid concentrations were determined for 4 h; here the sensitive moment in time for lunch was determined. Subjects came for a second set of experiments and received the same custards for breakfast, and an ad libitum lunch was offered at 180 min after breakfast; energy intake was assessed. There were increased scores of fullness and satiety after the 25 En% casein-custard compared with the 10 En% casein-custard, particularly at 180 min (26 (sem 4) v. 11 (sem 5) mm VAS; P < 0.01) and 240 min (13 (sem 5) v. - 1 (sem 5) mm VAS; P < 0.01). This coincided with prolonged elevated plasma amino acid concentrations; total amino acids and branched-chain amino acids were higher after the 25 En% casein-custard compared with the 10 En% casein-custard at 180 and 240 min (P < 0.001). There was no difference in energy intake (3080 (sem 229) v. 3133 (sem 226) kJ for 25 En% and 10 En% respectively; NS) from the ad libitum lunch. In conclusion, a breakfast with 25 % of energy from casein is rated as being more satiating than a breakfast with 10 % of energy from casein at 3 and 4 h after breakfast, coinciding with prolonged elevated concentrations of plasma amino acids, but does not reduce subsequent energy intake.
Veldhorst, M. A. B., Nieuwenhuizen, A. G., Waelen, A., Westerterp, K. R., Engelen, M. P., Brummer, R. J., Deutz, N. E. P., & Westerterp-Plantenga, M. S. (2009). Comparison of the effects of a high- and normal-casein breakfast on satiety, 'satiety' hormones, plasma amino acids and subsequent energy intake. British Journal of Nutrition, 101(2), 295-303. https://doi.org/10.1017/S0007114508003061