Supplementation of a Leucine-Enriched Dairy Protein Blend: Chronic and Acute Metabolic Responses in Young Men and Women
试验速览
- 阶段
- 早期 1 期
- 状态
- 已完成
- 入组人数
- 8
- 试验地点
- 2
- 主要终点
- Integrated Muscle Protein Synthetic Rate
研究概览
简要总结
It is well known that dietary protein transiently stimulates muscle protein synthesis (MPS) whereby changes in MPS in response to feeding may be regulated by specific downstream target proteins of mammalian target of rapamycin signaling, such as S6K1, rpS6, and eIF2B. A meal deficient in protein, however, does not increase the rate of MPS because a rise in the bioavailability of amino acids does not occur. In addition, the source of dietary proteins has been shown to impact postprandial blood levels of amino acids. The concept that certain types of proteins are "fast acting" or "slow acting" has been shown to affect the postprandial profile of amino acids appearing in the systemic circulation. Native whey and micellar casein are both dairy proteins that contain a similar amount of essential (EAA), but blood EAA levels increase faster and to a higher level after the consumption of whey protein. Differences in gastric emptying, digestion and absorption kinetics between micellar casein and native whey are the underlying factors. Nonetheless, micellar casein protein has been shown to protract MPS in humans. Despite the significant amount of information gained with respect to both of these protein sources, the effects of combinatorial formulations on the postprandial profile of amino acids appearing in the blood is less well known.
详细描述
In a cross-over, randomized controlled trial, 10 healthy young participants (5 men and 5 women) will be recruited to undergo exercise resistance training randomized to habitual diet or habitual diet and supplementation (2 x per training session). For two of the training sessions the investigators will utilize a uni-lateral resistance exercise model to identify the acute effects of exercise and exercise + supplementation on the integrated rate of myofibrillar MPS within subject. This model enhances statistical power and eliminates between-subject differences impacting our outcomes. Throughout the study participants will record their macronutrient dietary intake. In addition, baseline body composition will be assessed with dual-energy x-ray absorptiometry.
Visit 1 (Day -7): Familiarization, strength testing and baseline body composition One week before the exercise trial, the investigators will ask participants to visit McMaster University to undergo a familiarization session with the exercise equipment and to perform 3-5 repetition maximum strength testing. This will allow the investigators to calculate the resistance (weight) participants will lift in their upcoming training sessions. The investigators will also perform a body composition scan using a dual-energy x-ray absorptiometry (DXA), assess participants' height and weight, and administer daily food logs with instructions to assess their habitual diet.
Visit 2 (Day 0): D2O administration and resting blood and saliva sampling One week after the familiarization visit, the investigators will ask participants to come to McMaster University in a fasted state and receive a dose of doubly labelled water D2O equal to 0.8mLs/kgBW and every hour for 3 hours after providing a blood and saliva sample. D2O is a safe, and widely used stable isotope, used to effectively measure the rate at which participants' muscle grow.
Visits 3 and 7 (Days 1 and 7): Resistance training program and muscle biopsy On these days participants will come to the lab in the morning following their habitual diet routine and will have a resting biopsy, blood and saliva samples taken. Next, participants may be asked to consume the supplement but will be asked to drink a small amount of D2O. Finally, participants will perform a combination resistance style exercise training session and immediately following training may be asked to consume the supplement.
Visit 4, 5, 8 & 9 (Days 2, 3, 8, 9): Resistance training program On these days participants will come to the lab in the morning following their habitual diet routine and have a saliva sample taken. Next, participants may be asked to consume the supplement but will be asked to drink a small amount of D2O. Finally, participants will perform a combination resistance style exercise training session and immediately following training participants may be asked to consume the supplement.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 29 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Be between the ages of 18-29 years (inclusive)
- •Be able to maintain a habitual diet, physical activity patterns, and body mass throughout the trial
- •Be in general good health
- •Be able to participate in resistance training and aerobic training
- •Understand the study procedures and sign this form providing informed consent to participate in the study
- •Be able to consume a protein bar in the allotted time frame of 10 minutes
排除标准
- •Excessive alcohol consumption (more than 21 units of alcohol / week; 1 unit of alcohol is approximately 25 mL of spirits (40% alcohol), 250 mL of beer (4% alcohol) or 75 mL of wine (13% alcohol))
- •Have health problems such as: renal or gastrointestinal disorders, metabolic disease, heart disease, vascular disease, rheumatoid arthritis, diabetes, poor lung function, uncontrolled blood pressure, dizziness, thyroid problems, or any other health conditions for which you are being treated that might put you at risk for this study
- •Have a known or suspected allergy to local anesthetics such as lidocaine
- •Have a dairy protein allergy
- •Participation in another nutrition or exercise research study
- •Do not understand English or have a condition the PI believes would interfere with a participants' ability to provide informed consent, comply with the study protocol, or which might confound the interpretation of the study results or put someone at undue risk
- •Use of medications known to affect protein metabolism (i.e. corticosteroids, or prescription strength acne medications)
- •Consuming a vegan diet
- •Use of an investigational drug product or nutraceutical within the last 30 days
- •Any concurrent medical, orthopedic, or psychiatric condition that, in the opinion of the Investigators, would compromise the ability to comply with the study requirements
结局指标
主要结局
Integrated Muscle Protein Synthetic Rate
时间窗: 10 days
oral deuterium consumption: Isotope protocol (See ref., PMID 23821570)
次要结局
未报告次要终点
研究者
Stuart Phillips
Professor
McMaster University