A Meal-based Comparison of Protein Quality, Complementary Proteins and Muscle Anabolism

Study Overview
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Brief Summary
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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
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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.

Official Title
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A Meal-based Comparison of Protein Quality, Complementary Proteins and Muscle Anabolism

Conditions
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Protein, Diet, Skeletal Muscle

Intervention / Treatment
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* Other: PRO-A
* Other: PRO-B
* Other: PRO-C


Participation Criteria
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Eligibility Criteria
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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 Pregnancy

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PRO-A<br>Beef protein | Other: PRO-A<br>* 30 g of beef protein will be consumed at each meal<br>|
| Experimental: PRO-B<br>Complementary proteins at each meal | Other: PRO-B<br>* 30 g of complementary proteins will be consumed at each meal<br>|
| Experimental: PRO-C<br>Complementary proteins over 24 hours | Other: PRO-C<br>* 30 g of complementary proteins will be consumed over 24 hours<br>|
| No Intervention: CON<br>Low protein (<5 g) meal | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acute muscle protein synthesis: PRO-A | Muscle protein synthesis response to PRO-A breakfast meal (%/h) | 3 hours after consuming meal | 
| Acute muscle protein synthesis: PRO-B | Muscle protein synthesis response to PRO-B breakfast meal (%/h) | 3 hours after consuming meal | 
| Acute muscle protein synthesis: PRO-C | Muscle protein synthesis response to PRO-C breakfast meal (%/h) | 3 hours after consuming meal | 
| Acute muscle protein synthesis: CON | Muscle protein synthesis response to CON breakfast meal (%/hour) | 3 hours after consuming meal | 
| 24-hour muscle protein synthesis: PRO-A | Muscle protein synthesis response to PRO-A diet over 24 hours (%/hour) | Approximately 24 hours | 
| 24-hour muscle protein synthesis: PRO-B | Muscle protein synthesis response to PRO-B diet over 24 hours (%/hour) | Approximately 24 hours | 
| 24-hour muscle protein synthesis: PRO-C | Muscle protein synthesis response to PRO-C diet over 24 hours (%/hour) | Approximately 24 hours | 
| Blood amino acid response to diet: PRO-A | Blood samples will be drawn to measure amino acid concentrations response to PRO-A breakfast (µmol/L) | Approximately 5 hours | 
| Blood amino acid response to diet: PRO-B | Blood samples will be drawn to measure amino acid concentrations response to PRO-B breakfast (µmol/L) | Approximately 5 hours | 
| Blood amino acid response to diet: PRO-C | Blood samples will be drawn to measure amino acid concentrations response to PRO-B C breakfast (µmol/L) | Approximately 5 hours | 
| Blood amino acid response to diet: CON | Blood samples will be drawn to measure amino acid concentrations response to CON breakfast (µmol/L) | Approximately 5 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood glucose response to diet: PRO-A | Blood samples will be drawn to measure blood glucose response to PRO-A diet (mg/dl) | Approximately 24 hours | 
| Blood glucose response to diet: PRO-B | Blood samples will be drawn to measure blood glucose response to PRO-B diet (mg/dl) | Approximately 24 hours | 
| Blood glucose response to diet: PRO-C | Blood samples will be drawn to measure blood glucose response to PRO-C diet (mg/dl) | Approximately 24 hours | 
| Blood glucose response to diet: CON | Blood samples will be drawn to measure blood glucose response to CON breakfast meal (mg/dl) | Approximately 5 hours | 
| Appetite and Hedonic Questionnaire: PRO-A | Questionnaires will be given to assess hunger, fullness, desire to eat, thirst, desire to eat something sweet, desire to eat something salty, desire to eat something savory, sleepiness, physical energy, mental energy, and nausea in response to PRO-A diet. All outcomes are scored individually on a 10 pt visual analog scale using not at all being 0 and extremely being a 10. | Approximately 8 hours | 
| Appetite and Hedonic Questionnaire: PRO-B | Questionnaires will be given to assess hunger, fullness, desire to eat, thirst, desire to eat something sweet, desire to eat something salty, desire to eat something savory, sleepiness, physical energy, mental energy, and nausea in response to PRO-B diet. All outcomes are scored individually on a 10 pt visual analog scale using not at all being 0 and extremely being a 10. | Approximately 8 hours | 
| Appetite and Hedonic Questionnaire: PRO-C | Questionnaires will be given to assess hunger, fullness, desire to eat, thirst, desire to eat something sweet, desire to eat something salty, desire to eat something savory, sleepiness, physical energy, mental energy, and nausea in response to PRO-C diet. All outcomes are scored individually on a 10 pt visual analog scale using not at all being 0 and extremely being a 10. | Approximately 8 hours | 
| Appetite and Hedonic Questionnaire: CON | Questionnaires will be given to assess hunger, fullness, desire to eat, thirst, desire to eat something sweet, desire to eat something salty, desire to eat something savory, sleepiness, physical energy, mental energy, and nausea in response to CON diet. All outcomes are scored individually on a 10 pt visual analog scale using not at all being 0 and extremely being a 10. | Approximately 5 hours | 
| 3 day dietary record: PRO-A | Diet records will be collected and analyzed with ASA24 to assess habitual energy intake the week prior to PRO-A study visit | Approximately 36 hours | 
| 3 day dietary record: PRO-B | Diet records will be collected and analyzed with ASA24 to assess habitual energy intake the week prior to PRO-B study visit | Approximately 36 hours | 
| 3 day dietary record: PRO-C | Diet records will be collected and analyzed with ASA24 to assess habitual energy intake the week prior to PRO-C study visit | Approximately 36 hours | 
| 3 day dietary record: CON | Diet records will be collected and analyzed with ASA24 to assess habitual energy intake the week prior to CON study visit | Approximately 36 hours | 
| Palatability Questionnaire:PRO-A | Questionnaires will be given to assess palatability of the PRO-A diet. Outcomes include the participants ranking of the food appearance, aroma intensity, aroma, flavor intensity, flavor, texture and overall appeal of the food. A 10 pt visual analog scale will be used to assess the subject's response with 0 being extremely dislike, 5 being neither like nor dislike and 10 being extremely like. | Approximately 8 hours | 
| Palatability Questionnaire:PRO-B | Questionnaires will be given to assess palatability of the PRO-B diet. Outcomes include the participants ranking of the food appearance, aroma intensity, aroma, flavor intensity, flavor, texture and overall appeal of the food. A 10 pt visual analog scale will be used to assess the subject's response with 0 being extremely dislike, 5 being neither like nor dislike and 10 being extremely like. | Approximately 8 hours | 
| Palatability Questionnaire:PRO-C | Questionnaires will be given to assess palatability of the PRO-C diet. Outcomes include the participants ranking of the food appearance, aroma intensity, aroma, flavor intensity, flavor, texture and overall appeal of the food. A 10 pt visual analog scale will be used to assess the subject's response with 0 being extremely dislike, 5 being neither like nor dislike and 10 being extremely like. | Approximately 8 hours | 
| Palatability Questionnaire:CON | Questionnaires will be given to assess palatability of the CON diet. Outcomes include the participants ranking of the food appearance, aroma intensity, aroma, flavor intensity, flavor, texture and overall appeal of the food. A 10 pt visual analog scale will be used to assess the subject's response with 0 being extremely dislike, 5 being neither like nor dislike and 10 being extremely like. | Approximately 5 hours |