Effects of Short-term Energy Deficit on Muscle Protein Turnover
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 24
- 试验地点
- 1
- 主要终点
- Muscle protein turnover
研究概览
简要总结
Weight loss through energy restriction results in the loss of both fat and muscle mass. Muscle mass is important for mobility, strength, glucose control and energy expenditure, and therefore the retention of muscle mass during energy restriction is an important goal. The retention of muscle mass depends on the balance between muscle protein synthesis (MPS) and muscle protein breakdown (MPB). It is well known that MPS is reduced during weight loss, however the effect of weight loss on MPB is currently a topic of debate. The purpose of this study is to assess the effect of short-term (10 day) weight loss (40% energy deficit) on both MPS and MPB in order to gain insight into the mechanisms causing muscle loss during energy restriction. In addition, the effect of resistance exercise and protein (both known to preserve muscle mass) on MPS and MPB will be examined
详细描述
An undesirable consequence of energy restriction is the loss of muscle mass. Muscle mass is determined by the the rates of two processes: muscle protein synthesis and muscle protein breakdown. It has been consistently shown that a reduced rate of muscle protein synthesis exists during energy restriction. However, it is currently unclear whether an increase in muscle protein breakdown also contributes to muscle mass loss. In addition, the effect of high protein diets and resistance exercise on muscle protein turnover during energy restriction, two interventions known to preserve muscle, remains to be investigated.We aim to demonstrate that the decrease in muscle protein synthesis is the main contributor to a negative protein balance during energy restriction. In addition, we hope to show that a higher-protein diet (2.4g/kg/d versus 1.2g/kg/d) and the addition of resistance exercise can help to maintain the muscle protein synthesis rate and thereby improve negative protein balance.The present study will be designed as a parallel group randomized controlled trial. Subjects will be given pre-packaged diets (Copper County Foods) to consume which will put them in a relative energy deficit of 40% per day. Based on random assignment, these subjects will either consume an adequate protein diet (1.2g/kg/d) or a high protein diet (2.4g/kg/d) for 10 consecutive days. Participants in the adequate protein diet will consume a ratio of 50:35:15 (carbohydrates:fat:protein) while subjects within the high protein diet will consume a ratio of 50:15:35 (carbohydrates:fat:protein). Subjects will undergo testing at baseline and following a 10 day dietary and unilateral resistance exercise intervention. Testing will consist of muscle and blood samples. Muscle protein synthesis and muscle protein breakdown will be measured using stable isotope tracers that are orally ingested (deuterated water) or infused into an antecubital vein (labelled phenylalanine tracers) before and after the 10 day diet.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 20 Years 至 30 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •Between the ages of 20 and 30 years inclusive
- •Have a BMI between 25 and 33 inclusive
排除标准
- •Have a body mass index less than 25 kg/m2 or greater than 33 kg/m
- •History of allergy, sensitivity, or strong dislike towards dairy protein
- •Smoker or user of tobacco products
- •High physical activity
- •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 volunteers are being treated that might put them at risk for this study.
- •Taking anti-diabetic, anti-inflammatory, platelet inhibitor, or anti-coagulant medications
- •Use of an investigational drug product within the last 30 days
- •Have participated in an infusion protocol in the last year
- •Do not understand English or have a condition the PI believes would interfere with the ability to provide informed consent, comply with the study protocol, or which might confound the interpretation of the study results or put volunteers at undue risk
研究组 & 干预措施
High Protein
2.4g protein/kg/d. The macronutrient composition will be 50:15:35 (carbohydrates:fat:protein) during Energy Restriction
干预措施: Energy Restriction (Other)
Adequate Protein
1.2g protein/kg/d. The macronutrient composition will be 50:35:15 (carbohydrates:fat:protein) during Energy Restriction
干预措施: Energy Restriction (Other)
结局指标
主要结局
Muscle protein turnover
时间窗: Baseline and 10 days
Change in muscle protein synthesis and muscle protein breakdown before and after the weight loss diet will be assessed. The relationship between high protein diets (parallel groups) and exercise (unilateral resistance exercise) on muscle protein turnover will also be examined. Muscle protein synthesis and muscle protein breakdown will be measured with stable isotope infusions of labelled phenylalanine tracers before and after the 10 day diet. In addition, long term muscle protein synthesis will be measured with orally ingested deuterated water.
次要结局
- Molecular markers(Baseline and 10 days)
研究者
Stuart M. Phillips
Professor
McMaster University