Effect of Dietary Protein Intake Distribution on Protein Metabolism and Skeletal Muscle

The investigators determined effects of 8-week dietary protein intake in mixed meals with uneven or even consumption pattern on the metabolic outcomes of whole-body net protein synthesis and muscle protein synthesis in older participants.

Study Overview

• Status: Completed
• Conditions: Sarcopenia
• Intervention / Treatment: Other: Uneven Protein intake pattern; Other: Even Protein Intake Pattern

Detailed Description

The demonstrated benefits of increased protein intake on sarcopenia and many physiological functions is becoming increasingly evident. For this reason, there is growing importance to ensuring that Americans consume the recommended amount of protein, calculated to be 17-21% of caloric intake. As it relates to the prevention of sarcopenia, adequate protein consumption inherently assumes that sufficient protein is ingested to stimulate protein anabolism. Specifically, adequate essential amino acid precursors, and anabolic triggers such as leucine, must be present for protein anabolism to occur. Population data from the NHANES study suggests that American protein intake pattern is skewed towards the evening meal. The NHANES data also suggests that the average protein consumption of both men and women over the age of 50 yrs is approximately 1.1 g/kg/d. Thus, the prevalent consumption pattern ensures that many individuals consume adequate protein, or amino acid precursors sufficient to stimulate protein synthesis, only with the larger, or dinner meal. The investigators have demonstrated that frequent stimulation of protein synthesis with amino acids preserves strength and function. Others have demonstrated that adequate protein intake stimulates muscle protein synthesis and increases lean mass. Given these data, The investigators studied the effects of two different protein intake patterns on metabolic and functional outcomes in older individuals after 8 wks of dietary control. The mean protein intake for this group of 1.1 g/kg/d was consumed in two distinct meal patterns. Participants consumed high quality protein in the ratio of 15/20/65% of total protein intake for breakfast/lunch/dinner, respectively (Uneven protein intake pattern), or protein consumption was distributed equally among each meal (33% of total protein)(Even protein intake pattern). The investigators determined the longitudinal effects of this consumption pattern on the metabolic outcomes of whole-body net protein synthesis and muscle protein synthesis in older participants.

• Study Type: Interventional
• Enrollment (Actual): 19
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 70 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Men and women, ages 50-70 years
• BMI between 24 and 30 kg/m2

Exclusion Criteria:

• Current diagnosis of diabetes
• History of malignancy in the 6 months prior to enrollment
• History of lactose intolerance or dairy allergy
• History of egg allergy or intolerance
• History of gastrointestinal bypass surgery.
• History of a chronic inflammatory condition or other chronic disease (Lupus, HIV/AIDS, etc)
• Subjects who do not or will not eat animal proteins
• Subjects who cannot refrain from consuming protein or amino acid supplements during their participation in this study
• Subjects who report regular resistance exercise (more than twice per week)
• Hemoglobin less than 9.5 mg/dL at the screening visit
• Platelets less than 150,000 at the screening visit
• Concomitant use of corticosteroids (ingestion, injection or transdermal)
• Any other disease or condition that would place the subject at increased risk of harm if they were to participate, at the discretion of the study physician

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Uneven Protein Intake Pattern; Subjects consumed either dietary protein intake at 1.1g protein/kg/day over 8 weeks.Each participant will consume 15%/2-%/65% of total protein in breakfast, lunch, and dinner, respectively)] on net protein synthesis over 8 weeks.	Other: Uneven Protein intake pattern; Each participant will consume 15%/2-%/65% of total protein in breakfast, lunch, and dinner, respectively)] on net protein synthesis over 8 weeks.
EXPERIMENTAL: Even Protein Intake Pattern; Subjects consumed either dietary protein intake at 1.1g protein/kg/day over 8 weeks. Each participant will consume 33% of total protein consumed each meal	Other: Even Protein Intake Pattern; Each participant will consume 33% of total protein consumed each meal

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Changes in net protein synthesis rate	Change from Baseline to 8 weeks

Collaborators and Investigators

• Sponsor: University of Arkansas

Publications and helpful links

General Publications

• Kim IY, Schutzler S, Schrader AM, Spencer HJ, Azhar G, Wolfe RR, Ferrando AA. Protein intake distribution pattern does not affect anabolic response, lean body mass, muscle strength or function over 8 weeks in older adults: A randomized-controlled trial. Clin Nutr. 2018 Apr;37(2):488-493. doi: 10.1016/j.clnu.2017.02.020. Epub 2017 Mar 3.

Study record dates

Study Major Dates

• Study Start: January 1, 2014
• Primary Completion (ACTUAL): May 1, 2015
• Study Completion (ACTUAL): May 1, 2015

Study Registration Dates

• First Submitted: May 12, 2016
• First Submitted That Met QC Criteria: May 26, 2016
• First Posted (ESTIMATE): June 1, 2016

Study Record Updates

• Last Update Posted (ESTIMATE): June 1, 2016
• Last Update Submitted That Met QC Criteria: May 26, 2016
• Last Verified: May 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Neuromuscular Manifestations; Pathological Conditions, Anatomical; Muscular Atrophy; Atrophy; Sarcopenia
• Other Study ID Numbers: 139057