Abstract：
Glycomacropeptide (GMP) has a unique amino acid profile which may make less satiating than other dietary proteins. This study assessed the feasibility and likely acceptability of a leucine-enriched GMP drink and determined appetite response in older adults (OA). Thirteen OA (11f; 70 ± 4 years) were recruited for sensory assessments of a leucine-enriched GMP drink when mixed with water and with fruit smoothie, compared with whey protein isolate (WHEY). Participants also partook in a single focus group exploring acceptability to protein and supplementation. Separately, a counterbalanced, double-blind study with twelve OA (8f; 69 ± 3 years) was conducted to determine appetite and gut hormone responses. Fasting subjective appetite was recorded using visual analogue scales and a fasted venous blood sample was collected (to measures acyl-ghrelin, PYY, GLP-1, and CCK) before participants consumed either: GMP protein (27g + 3g leucine, 350 mL water), WHEY (30g, 350 mL water), or water. Participants rested for 240 min, with appetite measures and blood sampling throughout. An ad libitum pasta-based meal was then consumed. Sensory testing revealed low pleasantness rating for GMP in water vs. WHEY (16 ± 14 vs 31 ± 24, p = 0.016). GMP addition to smoothie reduced pleasantness (26 ± 21 vs. 61 ± 29, p = 0.009) and worsened the aroma (46 ± 15 vs. 69 ± 28, p = 0.014). The focus group revealed uncertainty of protein needs and a scepticism of supplements, with preference for food. Gut hormone response did not differ between GMP and WHEY (nAUC for all gut hormones p > 0.05). There was no difference between conditions for lunch ad libitum intake (549 ± 171 kcal, 512 ± 238 kcal, 460 ± 199 kcal for GMP, WHEY, and water, p = 0.175), or for subjective appetite response. Leucine-enriched GMP was not less satiating than WHEY, and low palatability and scepticism of supplements question the likely acceptability of GMP supplementation. Providing trusted nutritional advice and food enrichment/fortification may be preferred strategies for increasing protein intake in OA.
摘要：
糖巨肽（GMP）具有独特的氨基酸谱，可能比其他饮食蛋白质的饱腹感更低。这项研究评估了富含亮氨酸的GMP饮料的可行性和可能的可接受性，并确定了老年人（OA）的食欲反应。当与水和水果冰沙混合时，招募了13个OA（11f;70±4年）用于富含亮氨酸的GMP饮料的感官评估，与乳清分离蛋白(WHEY)相比。参与者还参加了一个单一的焦点小组，探索蛋白质和补充剂的可接受性。分别,一个平衡的，进行了12个OA（8f;69±3年）的双盲研究，以确定食欲和肠道激素反应。使用视觉模拟量表记录空腹主观食欲，并收集空腹静脉血样本（以测量酰基生长素释放肽，PYY,GLP-1和CCK）在参与者食用前：GMP蛋白（27g+3g亮氨酸，350mL水)，WHEY(30g,350mL水)，或者水。参与者休息了240分钟，通过食欲测量和血液采样。然后食用基于意大利面食的随意膳食。感官测试表明，水中GMP的愉悦等级较低，而不是WHEY(16±14vs31±24,p=0.016)。GMP添加到冰沙降低了愉悦感（26±21vs.61±29，p=0.009），香气恶化（46±15与69±28，p=0.014）。焦点小组揭示了蛋白质需求的不确定性和对补充剂的怀疑，偏爱食物。GMP和WHEY之间的肠道激素反应没有差异（所有肠道激素的nAUCp>0.05）。随意摄入午餐的条件之间没有差异(549±171千卡，512±238千卡，GMP为460±199千卡，Whey,和水，p=0.175)，或主观食欲反应。富含亮氨酸的GMP的饱腹感不亚于WHEY，以及补充剂的低适口性和怀疑性质疑GMP补充剂的可能可接受性。提供可信的营养建议和食物富集/强化可能是增加OA中蛋白质摄入的优选策略。
