Αcute effects of essential amino acid gel-based and whey protein supplements on appetite and energy intake in older women

Deficiencies in protein and energy intakes are partly responsible for age-related sarcopenia. We investigated the effects of supplements matched in essential amino acid (EAA) content (7.5 g) on energy intake and appetite. Ten women aged 69.2 ± 2.7 years, completed three trials in a randomised, crossover design. Composite appetite scores, peptide-YY (PYY), and insulin responses to a 200 ml whey protein isolate (WP, 275 kJ), a 50 ml EAA gel (GEL, 478 kJ) or nothing as the control condition (CON) were investigated over one hour, followed by an ad libitum breakfast. Energy intake at breakfast (CON 1957 ± 713, WP 1413 ± 623, GEL 1963 ± 611 kJ) was higher in CON and GEL than in WP (both P = 0.006). After accounting for supplement energy content, energy intake in GEL was higher than in CON (P = 0.0006) and WP (P = 0.0008). Time-averaged area under the curve for composite appetite scores (CON 74 ± 20, WP 50 ± 22, GEL 60 ± 16 mm) was higher in CON than WP (P = 0.015). Time-averaged area under the curve for PYY (CON 87 ± 13, WP 119 ± 27, GEL 97 ± 22 pg·mL-1) was higher in WP than CON (P = 0.009) and GEL (P = 0.012). In conclusion, supplementation with WP facilitated an increase in protein intake, whereas supplementation with GEL increases in both energy and protein intakes, when consumed before an ad libitum breakfast. Such findings, highlight potential gel-based EAA supplementation intake for addressing age-related sarcopenia.