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Trial registered on ANZCTR


Registration number
ACTRN12612000177853
Ethics application status
Approved
Date submitted
1/02/2012
Date registered
9/02/2012
Date last updated
12/09/2013
Type of registration
Prospectively registered

Titles & IDs
Public title
Optimal diet patterns for improving muscle strength in older adults
Scientific title
A 12 week randomised controlled trial investigating the optimal dietary pattern for improving muscle strength in older adults undertaking resistance training
Secondary ID [1] 279818 0
none
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Loss of muscle mass and strength in aging 285704 0
Condition category
Condition code
Musculoskeletal 285886 285886 0 0
Other muscular and skeletal disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
All participants will undertake three 60 minute resistance training sessions per week on non-consecutive days for 3 months. Participants will perform the exercises on their own with the supervision of gym staff. The program will progress from 1-3 sets of 8-12 repetitions for 6 upper and lower body exercises starting at 100% 8RM measured at baseline. They will be randomised to one of three dietary patterns for three months: high carbohydrate, high dairy protein or high soy protein. Participants will meet fortnightly with a dietician to discuss the diet plan. The high dairy protein group is the intervention under investigation and participants will be prescribed to consume a healthy low fat diet, with one serve of dairy, designed to provide ~1.0 g/kg/day of dietary protein. In addition they will consume snack foods, with an additional ~27 g/day of dairy-based protein from 3 serves of dairy foods to provide a total protein intake of ~1.3-1.4 g/kg/day. The 3 serves will be consumed after resistance exercise training. On non-training days the serves will be consumed as part of their breakfast.
Intervention code [1] 284138 0
Prevention
Intervention code [2] 284163 0
Lifestyle
Comparator / control treatment
They will be randomised to one of three dietary patterns for three months: high carbohydrate, high dairy protein or high soy protein. Participants will meet fortnightly with a dietician to discuss the diet plan. The high carbohydrate and high soy protein diets are the control groups to allow for the determination of the efficacy of the high protein diet and in particular dairy protein. Participants allocated the high protein soy diet will be prescribed to consume a healthy low fat diet, with one serve of dairy, designed to provide ~1.0 g/kg/day of dietary protein, with an additional ~27g/day of non-dairy based protein from three serves of soy protein based foods to provide a total protein intake of ~1.3-1.4 g/kg/day. Three serves of soy protein (~27g protein) will be consumed after resistance exercise training. On non-training days the soy protein will be consumed as part of their breakfast. Participants allocated the high carbohydrate diet will be prescribed to consume a healthy low fat diet, with one serve of dairy, designed to provide ~1.0 g/kg/day of dietary protein, and a high carbohydrate food supplement, which will provide ~3g/kg/day of carbohydrates. These foods will be consumed after resistance exercise training. On non-training days participants will consume the foods at a time that is convenient to them.
Control group
Active

Outcomes
Primary outcome [1] 286381 0
Changes in 1 repetition maximum of chest press, lateral pull down, leg press, knee extension and leg curl assessed on gym equipment
Timepoint [1] 286381 0
There are 2 timepoints, baseline (week 0) and at the end of the intervention at Week 12
Secondary outcome [1] 295740 0
Changes in isometric knee extensor muscle strength assessed by an isokinetic dynamometer
Timepoint [1] 295740 0
There are 2 timepoints, baseline (week 0) and at the end of the intervention at Week 12
Secondary outcome [2] 295741 0
Changes in body composition assessed by lean tissue and body fat mass by dual energy x-ray absorptiometry, weight and waist circumference.
Timepoint [2] 295741 0
There are 2 timepoints, baseline (week 0) and at the end of the intervention at Week 12
Secondary outcome [3] 295742 0
Changes in grip strength of the dominant hand using an adjustable, hydraulic handgrip dynamometer
Timepoint [3] 295742 0
There are 2 timepoints, baseline (week 0) and at the end of the intervention at Week 12
Secondary outcome [4] 295743 0
Changes in physical function assessed using the six minute walk, De Morton Mobility Index and Human activity profile
Timepoint [4] 295743 0
There are 2 timepoints, baseline (week 0) and at the end of the intervention at Week 12
Secondary outcome [5] 295744 0
Changes in quality of life assessed using the short-form 36 questionnaire
Timepoint [5] 295744 0
There are 2 timepoints, baseline (week 0) and at the end of the intervention at Week 12
Secondary outcome [6] 295745 0
Changes in cardiometabolic risk factors assessed using analysis of fasting blood lipids, glucose and insulin
Timepoint [6] 295745 0
There are 2 timepoints, baseline (week 0) and at the end of the intervention at Week 12
Secondary outcome [7] 295746 0
Changes in urea and creatinine from a 24 hour urine sample
Timepoint [7] 295746 0
There are 2 timepoints, baseline (week 0) and at the end of the intervention at Week 12

Eligibility
Key inclusion criteria
Aged 50-79 yrs
BMI 20-35 kg/m2
Stable medication for at least 3 months
Minimum age
50 Years
Maximum age
79 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Diagnosed with diabetes (type 1 or type 2 diabetes), proteinuria, a malignancy, or a history of metabolic disease such as liver, kidney, cardiovascular, respiratory or gastrointestinal disease, cardiac abnormalities or are pregnant or lactating
Uncontrolled hypertension
Currently have or history of a musculoskeletal injury, joint or peripheral vascular disease sufficient to impede their participation in the exercise program (such as hip arthritis, foot, ankle problems or pain)
Current smoker or history of smoking during last 6 months Heavy alcohol consumption (> 5 STD drinks/day) or unable to limit intake for study duration (upper limit of 2-7 STD drinks/wk)
Participated in regular formal aerobic or resistance exercise program (greater than two 30-min sessions of moderate/vigorous aerobic exercise per week or greater than 1 moderate intensity resistance exercise session per week) during the 6 months prior to study
Widely fluctuating exercise patterns
Currently on a weight reducing diet
Intolerant/allergic to lactose or bovine milk protein
Untreated depression
Currently using or recent (3 months) use of testosterone therapy

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Subjects will be recruited by newspaper advertisement and flyers. Volunteers will be screened via questionnaire and a medical screening visit to access their eligibility for the trial. Eligibility will be determined by the study coordinator and medical physician. Treatment will be randomly allocated by the trial manager after eligibility is determined and will only be told to the dietician administering the dietary patterns. Allocation will be concealed from the study staff conducting the outcome assessments at a different site. The participants will know which group they have been allocated to because they will have to follow the required dietary pattern.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Allocation to treatments will be via the process of minimisation on the basis of gender, BMI and age.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 284599 0
Commercial sector/Industry
Name [1] 284599 0
Dairy Health and Nutrition Consortium
Address [1] 284599 0
671 Sneydes Road
Werribee, Victoria 3030
Country [1] 284599 0
Australia
Primary sponsor type
University
Name
University of South Australia
Address
GPO Box 2471
Adelaide SA 5001
Country
Australia
Secondary sponsor category [1] 283517 0
None
Name [1] 283517 0
Address [1] 283517 0
Country [1] 283517 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 286582 0
University of South Australia Human Research Ethics Committee
Ethics committee address [1] 286582 0
General Purpose Building, Mawson Lakes Campus Mawson Lakes Boulevard Mawson Lakes, SA 5095
Ethics committee country [1] 286582 0
Australia
Date submitted for ethics approval [1] 286582 0
24/11/2011
Approval date [1] 286582 0
Ethics approval number [1] 286582 0
26921

Summary
Brief summary
The current project will investigate the best dietary pattern when combined with a regular weight training program for improving muscle strength, lean mass and physical function (i.e. tasks of daily living) in older adults. Participants will have to consume diet specific foods containing varying amounts of protein and carbohydrate within 1 hour after their exercise session as this has been shown as an important window for nutrition to stimulate an increase in muscle growth.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 33697 0
Prof Jon Buckley
Address 33697 0
Nutritional Physiology Research Centre University of South Australia GPO Box 2471 Adelaide SA 5001
Country 33697 0
Australia
Phone 33697 0
+61 8 8302 1853
Fax 33697 0
Email 33697 0
jon.buckley@unisa.edu.au
Contact person for public queries
Name 16944 0
Dr Rebecca Thomson
Address 16944 0
Nutritional Physiology Research Centre
University of South Australia
GPO Box 2471
Adelaide SA 5001
Country 16944 0
Australia
Phone 16944 0
+61 8 8302 1822
Fax 16944 0
Email 16944 0
rebecca.thomson@unisa.edu.au
Contact person for scientific queries
Name 7872 0
Prof Jon Buckley
Address 7872 0
Nutritional Physiology Research Centre
University of South Australia
GPO Box 2471
Adelaide SA 5001
Country 7872 0
Australia
Phone 7872 0
+61 8 8302 1853
Fax 7872 0
Email 7872 0
jon.buckley@unisa.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary