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

University of Arkansas

Status: Completed

Conditions: Sarcopenia

Treatments: Other: Even Protein Intake Pattern; Other: Uneven Protein intake pattern

Study type: Interventional

Funder types: Other

Identifiers

NCT02787889

139057

Details and patient eligibility

About

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.

Full 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.

Enrollment: 19 patients

Sex: All

Ages: 50 to 70 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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19 participants in 2 patient groups

Uneven Protein Intake Pattern

Experimental group

Description:

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.

Treatment:

Other: Uneven Protein intake pattern

Even Protein Intake Pattern

Experimental group

Description:

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

Treatment:

Other: Even Protein Intake Pattern