Skeletal Muscle Protein Metabolism and Insulin Sensitivity in Overweight Individuals: Effects of Meals With Various Fatty Acid Compositions

Study Overview
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Brief Summary
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The aim of the study will investigate whether impairment in the action of insulin to promote the use of glucose in skeletal muscle (insulin resistance) as a result of oral ingestion of a liquid meal rich in saturated fat is linked to reduced ability of muscles to synthesise new protein in response to dietary protein intake, which ultimately may compromise maintenance of muscle size and quality of life and whether partially replacing saturated fat in the liquid meal with omega 3 polyunsaturated FA (n3PUFA) will ameliorate these negative effects.

Official Title
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Skeletal Muscle Protein Metabolism and Insulin Sensitivity in Overweight Individuals: Effects of Meals With Various Fatty Acid Compositions

Conditions
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Insulin Resistance

Intervention / Treatment
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* Dietary Supplement: Saturated fat
* Dietary Supplement: Placebo
* Dietary Supplement: Fish Oil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male, healthy, overweight (BMI>27 kg/m2 and fat mass >30%) non-diabetic individuals. Exclusion Criteria: Diabetes, smoking, cardiovascular disease

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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Male

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: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control<br>Chocolate flavoured drink spiked with 15mg/kg [2H31]palmitate (D31palmitate) and singly-labelled water (H218O). 4 hours post test meal a bolus of milk protein (30 g), which has been intrinsically labelled with [13C]phenylalanine, along with 75 g of glucose in 250 ml of water will be given. | Dietary Supplement: Placebo<br>* Water<br>|
| Experimental: Saturated Fat<br>Chocolate flavoured drink spiked with 15mg/kg [2H31]palmitate (D31palmitate) and singly-labelled water (H218O) containing 0.7 g/kg bodyweight palm stearin. 4 hours post test meal a bolus of milk protein (30 g), which has been intrinsically labelled with [13C]phenylalanine, along with 75 g of glucose in 250 ml of water will be given. | Dietary Supplement: Saturated fat<br>* Palm stearin<br>|
| Experimental: Fish Oil<br>Chocolate flavoured drink spiked with 15mg/kg [2H31]palmitate (D31palmitate) and singly-labelled water (H218O) containing 0.45 g/kg bodyweight palm stearin and 0.25 g/kg bodyweight fish oil (n3PUFA). 4 hours post test meal a bolus of milk protein (30 g), which has been intrinsically labelled with [13C]phenylalanine, along with 75 g of glucose in 250 ml of water will be given. | Dietary Supplement: Fish Oil<br>* Fish Oil, Omega 3 PUFA<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in muscle protein fractional synthetic rate | Measurement of FSR at baseline and post intervention | 3 hours post protein drink | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| whole body postprandial insulin sensitivity | Glucose and insulin area under the curves (AUC) in response to the milk protein and glucose ingestion will be measured | Baseline and every 15mins for 7 hours | 
| Whole body and skeletal muscle fat oxidation | D31palmitate plasma enrichment and incorporation into skeletal muscle lipids | Baseline and every 15mins for 7 hours |