THE IMPACT OF ESSENTIAL AMINO ACID SUPPLEMENTS ENRICHED WITH L-LEUCINE ON APPETITE AND ENERGY INTAKE IN ELDERLY WOMEN

Rationale: Inadequate protein intake (PI), the main source of essential amino acids (EAAs), and reduced appetite are contributing factors to age-related sarcopenia. The satiating effects of dietary protein may negatively affect energy intake (EI), thus there is a need to explore alternative strategies to facilitate PI without compromising appetite and subsequent EI. Methods: Elderly women completed two experiments (EXP1&2) where they consumed either a Bar (B, 135 kcal) or a Gel (G, 114 kcal), rich in EAAs (7.5 g, 40% L-Leucine), or nothing [control (C)]. In EXP1, subjects (n=10, 68±5 years, mean±SD) consumed B, G or C with appetite sensations and appetite-related hormonal responses monitored for 1h, followed by consumption of an ad libitum breakfast (ALB). In EXP2, subjects (n=11, 69±5 years) ingested B, G or C alongside an ALB. Results: In EXP1, EI at ALB was not different (P=0.674) between conditions (282±135, 299±122, 288±131 kcal for C, B and G respectively). However, total EI was significantly higher in B and G compared to C after accounting for the energy content of the supplements (P<0.0005). Analysis revealed significantly higher appetite Area under the Curve (AUC) (P<0.007), a tendency for higher acylated ghrelin AUC (P=0.087), and significantly lower pancreatic polypeptide AUC (P=0.02) in C compared with B and G. In EXP2, EI at ALB was significantly higher (P=0.028) in C (306±122 kcal) compared to B (245±135 kcal) and G (254±118 kcal). However, total EI was significantly higher in B and G after accounting for the energy content of the supplements (P<0.007). Conclusion: Supplementation with either the bar or gel increased total energy intake whether consumed 1h before or during breakfast. This may represent an effective nutritional means for addressing protein and total energy deficiencies in elderly women.