Arentson-Lantz Emily J, Von Ruff Zachary, Connolly Gavin, Albano Frank, Kilroe Sean P, Wacher Adam, Campbell Wayne W, Paddon-Jones Douglas
Department of Nutrition Sciences and Health Behavior, University of Texas Medical Branch, Galveston, TX, United States; Center for Health Promotion, Performance and Rehabilitation Science, University of Texas Medical Branch, Galveston, TX, United States.
Center for Health Promotion, Performance and Rehabilitation Science, University of Texas Medical Branch, Galveston, TX, United States.
J Nutr. 2024 Dec;154(12):3626-3638. doi: 10.1016/j.tjnut.2024.10.010. Epub 2024 Oct 11.
Dietary protein quality can be assessed by skeletal muscle protein synthesis (MPS) stimulation. Limited knowledge exists on how consuming isonitrogenous meals with varied protein qualities affects postprandial and 24-h MPS.
We assessed the effects of protein quality and complementary proteins on MPS. We hypothesized that meals containing a moderate amount of high-quality, complete protein would stimulate postprandial and 24-h MPS. Meals containing two complementary, plant-based incomplete proteins would stimulate MPS less, and meals containing plant-based incomplete proteins at each meal, but complementary over 24 h would not stimulate MPS.
This quasi-experimental study included a randomized, crossover design to assess protein quality and a nonrandomized low-protein control. We measured postprandial and 24-h MPS responses of healthy middle-aged women (n = 9, age 56 ± 4 y), to 3 dietary conditions: isonitrogenous meals containing 23 g protein/meal from 1) complete protein (lean beef), 2) 2 incomplete, but complementary protein sources (navy/black beans and whole wheat bread), and 3) single incomplete protein sources (black beans or whole wheat bread at 1 meal), but providing a complete amino acid profile over 24 h. In the low-protein group women (n = 8, 54 ± 5 y) consumed a single breakfast meal containing 5 g of protein. Venous blood and vastus lateralis samples were obtained during primed, constant infusions of L-[ring-C]phenylalanine to measure mixed muscle fractional synthetic rates (FSR).
Meals containing complete, complementary, or incomplete proteins did not differentially influence FSR responses after breakfast (P = 0.90) or 24 h (P = 0.38). At breakfast, the complete (P = 0.030) and complementary (P = 0.031) protein meals, but not the incomplete protein meal (P = 0.38), had greater FSR responses compared with the low-protein control meal.
Isonitrogenous meals containing a moderate serving of total protein from foods providing complete, complementary, or incomplete essential amino acid profiles do not differentially stimulate muscle protein synthesis after a meal and daily.
This clinical trial was registered at clinicaltrials.gov as NCT03816579. URL: https://www.
gov/ct2/show/NCT03816579?term=NCT03816579&draw=2&rank=1.
膳食蛋白质质量可通过骨骼肌蛋白质合成（MPS）刺激来评估。关于摄入不同蛋白质质量的等氮餐如何影响餐后及24小时MPS的知识有限。
我们评估了蛋白质质量和互补蛋白质对MPS的影响。我们假设，含有适量优质完全蛋白质的餐食会刺激餐后及24小时MPS。含有两种互补植物性不完全蛋白质的餐食对MPS的刺激较小，而每餐含有植物性不完全蛋白质但在24小时内互补的餐食不会刺激MPS。
这项准实验研究采用随机交叉设计来评估蛋白质质量，并设置了非随机低蛋白对照。我们测量了健康中年女性（n = 9，年龄56±4岁）对3种饮食条件的餐后及24小时MPS反应：等氮餐，每餐含23克蛋白质，分别来自1）完全蛋白质（瘦牛肉），2）2种不完全但互补的蛋白质来源（海军豆/黑豆和全麦面包），以及3）单一不完全蛋白质来源（一餐食用黑豆或全麦面包），但在24小时内提供完整的氨基酸谱。在低蛋白组中，女性（n = 8，54±5岁）食用一份含5克蛋白质的早餐。在给予L-[环-C]苯丙氨酸的预充、持续输注期间采集静脉血和股外侧肌样本，以测量混合肌肉分数合成率（FSR）。
含有完全、互补或不完全蛋白质的餐食对早餐后（P = 0.90）或24小时（P = 0.38）的FSR反应没有差异影响。早餐时，与低蛋白对照餐相比，完全蛋白质餐（P = 0.030）和互补蛋白质餐（P = 0.031）的FSR反应更大，而不完全蛋白质餐的FSR反应则无差异（P = 0.38）。
从提供完全、互补或不完全必需氨基酸谱的食物中摄入适量总蛋白质的等氮餐，在餐后和每日对肌肉蛋白质合成的刺激没有差异。
本临床试验在clinicaltrials.gov注册，注册号为NCT03816579。网址：https://www.clinicaltrials.gov/ct2/show/NCT03816579?term=NCT03816579&draw=2&rank=1。
