Optimal Protein Dose Per Meal During Weight Loss in Perspective to Maintaining Muscle Mass

Study Overview
=================
Brief Summary
-----------------
The primary aim of the trial is to determine the optimal dose of protein per meal in relation to enhancing muscle protein synthesis and thereby in perspective counteract muscle loss during weight loss. In addition, we aim to determine whether the response to protein intake is reduced in women on hypocaloric diet compared to in women on an energy-balanced diet.

Detailed Description
-----------------
Aim of this project is to determine the optimal protein dose (high quality milk protein) per meal in relation to enhancing muscle protein synthesis and thereby counteract muscle loss during weight loss. The hypothesis is that the optimum dose of protein for women on a hypocaloric diet will be greater than when women eat an energy sufficient diet, and also higher than the optimal dose previously determined in weight stable men. Methods: Forty women (  50 years) will be randomized to four groups. Following a five day hypocaloric diet (three groups) or an energy balanced diet (one group). The women will report to the laboratory to ingest one of three different protein doses. The muscle protein response to the different doses of protein will be determined by the muscle protein fractional synthetic rates using tracer kinetics.

Official Title
-----------------
Optimizing Per Meal Protein Intake During Weight Loss

Conditions
-----------------
Protein Metabolism

Intervention / Treatment
-----------------
* Other: 15 g protein hypocaloric
* Other: 35 g protein hypocaloric
* Other: 60 g protein hypocaloric
* Other: 35 g protein energy balance


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: healthy Postmenopausal women Exclusion Criteria: Smoking Metabolic and/or chronic diseases

Ages Eligible for Study
-----------------
Minimum Age: 45 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: : Forty women (  50 years) will be randomized to four groups. Following a five day hypocaloric diet (three groups) or an energy balanced diet (one group). The women will report to the laboratory to ingest one of three different protein doses.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 15g protein hypocaloric diet<br>Following a 5-day hypocaloric diet the subjects (n=10) will ingest 15g of protein and their mixed muscle protein synthesis response will be monitored using tracer kinetics. | Other: 15 g protein hypocaloric<br>* Following a 5 day hypocaloric diet one group of 10 women will ingest 15 g of protein<br>|
| Experimental: 35g protein hypocaloric diet<br>Following a 5-day hypocaloric diet the subjects (n=10) will ingest 35g of protein and their mixed muscle protein synthesis response will be monitored using tracer kinetics. | Other: 35 g protein hypocaloric<br>* Following a 5 day hypocaloric diet one group of 10 women will ingest 35 g of protein<br>|
| Experimental: 60g protein hypocaloric diet<br>Following a 5-day hypocaloric diet the subjects (n=10) will ingest 60g of protein and their mixed muscle protein synthesis response will be monitored using tracer kinetics. | Other: 60 g protein hypocaloric<br>* Following a 5 day hypocaloric diet one group of 10 women will ingest 60 g of protein<br>|
| Experimental: 35g protein energy balanced diet<br>Following a 5-day energy balanced diet the subjects (n=10) will ingest 35g of protein and their mixed muscle protein synthesis response will be monitored using tracer kinetics. | Other: 35 g protein energy balance<br>* Following a 5 day energy balanced diet one group of 10 women will ingest 35 g of protein<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fractional synthetic rate | Mixed muscle protein synthetic rate determined by tracer kinetics | 3 hours after ingestion of protein | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle signalling | Markers for myofibrillar protein turnover measured by RT-PCR and western blotting | 3 hours after ingestion of protein. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Hypocaloric diet, Dietary protein