A Meal-based Comparison of Protein Quality, Complementary Proteins and Muscle Anabolism
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Enrollment
- 23
- Locations
- 1
- Primary Endpoint
- Acute muscle protein synthesis: PRO-B
Study Overview
Brief Summary
To highlight the importance of protein quality rather than the total protein content of a meal, the investigators will demonstrate that unlike high quality proteins, a single meal containing 30 g of an incomplete protein source does not stimulate skeletal muscle protein synthesis. Secondly, the investigators will directly challenge a prevalent, but untested, assertion that has the potential to negatively impact health. The goal is to demonstrate that complementary plant-proteins (i.e., two or more incomplete protein sources) must be consumed at the same meal to stimulate protein synthesis.
Detailed Description
The investigators will test the following hypotheses in middle-aged men and women (45-60) years old using a randomized, cross over design. All study objectives will be met concurrently:
- Meals containing 30 g of high quality, predominantly beef-protein (PRO-A) will stimulate acute (i.e., single meal response) and 24 h skeletal muscle protein synthesis [confirmatory hypothesis]
- Meals containing 30 g of complementary plant-based proteins (PRO-B: complete essential amino acid profile at each meal) will stimulate acute and 24 h skeletal muscle protein synthesis, but to a lesser extent than beef-protein.
- A single meal containing 30 g of an incomplete plant-based protein source (PRO-C: lacking one essential amino acid) will fail to acutely stimulate skeletal muscle protein synthesis
- Meals containing 30 g of plant-based protein that are incomplete at each separate meal, but complementary over a 24 h period, will fail to stimulate 24 h skeletal muscle protein synthesis.
- Beef-and plant-based meals will have a similar effect on satiety and 24 h blood glucose [descriptive]
If these hypotheses are correct, the investigators will demonstrate that meals containing a moderate amount of high quality protein, such as beef, are an efficient and effective way to augment a largely plant based diet and stimulate skeletal muscle protein synthesis - a prerequisite for outcomes related to physical function, performance, successful aging and metabolic health.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Other
- Masking
- Single (Participant)
Eligibility Criteria
- Ages
- 45 Years to 60 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •All races and ethnic backgrounds
- •Men and women, age 45-60 years
- •Generally healthy (see
Exclusion Criteria
- •Able and willing to provide informed consent
- •Ability to speak and read English (* the study procedures, e.g., muscle biopsy, duration of each acute study, e.g. overnight stay; and multiple dietary questionnaires require sound written and spoken English)
- •Exclusion Criteria:
- •Sarcopenia (defined by: European Working Group on Sarcopenia in Older People, EWGSOP (44))
- •Clinically significant heart disease (e.g. New York Heart Classification greater than grade II; ischemia)
- •Peripheral vascular disease
- •Pulmonary disease
- •History of systemic or pulmonary embolus
- •Uncontrolled blood pressure (systolic BP>170, diastolic BP>95 mmHg)
- •Impaired renal function (creatinine >1.5 mg/dl)
- •Anemia (hematocrit <33)
- •Untreated thyroid disease (abnormal TSH)
- •A recent history (<12 months) of GI bleed
- •Diabetes mellitus or other untreated endocrine or metabolic disease
- •Electrolyte abnormalities
- •Any history of stroke, hypo- or hyper-coagulation disorders
- •Recent (3 years) treated cancer other than basal cell carcinoma
- •Systemic steroids, anabolic steroids, growth hormone or immunosuppressant use within 12 months
- •Recent (6 months) adherence to a weight-loss or weight-gain diet
- •Weight change of 5% or more in previous 6 months
- •Body mass index >30 or excess body fat that compromises muscle biopsy collection
- •Body mass index <20 or recent history (<12 month) of disordered eating
- •Dietary preferences or practices that preclude the consumption of the study meals
- •Acute infectious disease or chronic infection
- •Alcohol or drug abuse
- •Any other condition or event considered exclusionary by study physician
Arms & Interventions
PRO-A
Beef protein
Intervention: PRO-A (Other)
PRO-B
Complementary proteins at each meal
Intervention: PRO-B (Other)
PRO-C
Complementary proteins over 24 hours
Intervention: PRO-C (Other)
CON
Low protein (<5 g) meal
Outcomes
Primary Outcomes
Acute muscle protein synthesis: PRO-B
Time Frame: 3 hours after consuming meal
Muscle protein synthesis response to PRO-B breakfast meal (%/h)
Acute muscle protein synthesis: PRO-A
Time Frame: 3 hours after consuming meal
Muscle protein synthesis response to PRO-A breakfast meal (%/h)
Blood amino acid response to diet: PRO-A
Time Frame: Approximately 5 hours
Blood samples will be drawn to measure amino acid concentrations response to PRO-A breakfast (µmol/L)
24-hour muscle protein synthesis: PRO-B
Time Frame: Approximately 24 hours
Muscle protein synthesis response to PRO-B diet over 24 hours (%/hour)
Acute muscle protein synthesis: CON
Time Frame: 3 hours after consuming meal
Muscle protein synthesis response to CON breakfast meal (%/hour)
24-hour muscle protein synthesis: PRO-A
Time Frame: Approximately 24 hours
Muscle protein synthesis response to PRO-A diet over 24 hours (%/hour)
24-hour muscle protein synthesis: PRO-C
Time Frame: Approximately 24 hours
Muscle protein synthesis response to PRO-C diet over 24 hours (%/hour)
Blood amino acid response to diet: PRO-C
Time Frame: Approximately 5 hours
Blood samples will be drawn to measure amino acid concentrations response to PRO-B C breakfast (µmol/L)
Blood amino acid response to diet: CON
Time Frame: Approximately 5 hours
Blood samples will be drawn to measure amino acid concentrations response to CON breakfast (µmol/L)
Acute muscle protein synthesis: PRO-C
Time Frame: 3 hours after consuming meal
Muscle protein synthesis response to PRO-C breakfast meal (%/h)
Blood amino acid response to diet: PRO-B
Time Frame: Approximately 5 hours
Blood samples will be drawn to measure amino acid concentrations response to PRO-B breakfast (µmol/L)
Secondary Outcomes
- Blood glucose response to diet: PRO-A(Approximately 24 hours)
- 3 day dietary record: CON(Approximately 36 hours)
- Palatability Questionnaire:CON(Approximately 5 hours)
- Blood glucose response to diet: PRO-B(Approximately 24 hours)
- Blood glucose response to diet: PRO-C(Approximately 24 hours)
- Blood glucose response to diet: CON(Approximately 5 hours)
- Appetite and Hedonic Questionnaire: PRO-A(Approximately 8 hours)
- Appetite and Hedonic Questionnaire: PRO-B(Approximately 8 hours)
- Appetite and Hedonic Questionnaire: CON(Approximately 5 hours)
- 3 day dietary record: PRO-A(Approximately 36 hours)
- Palatability Questionnaire:PRO-C(Approximately 8 hours)
- Appetite and Hedonic Questionnaire: PRO-C(Approximately 8 hours)
- 3 day dietary record: PRO-B(Approximately 36 hours)
- 3 day dietary record: PRO-C(Approximately 36 hours)
- Palatability Questionnaire:PRO-A(Approximately 8 hours)
- Palatability Questionnaire:PRO-B(Approximately 8 hours)