Impact of High-fat Meals Varying in Fatty Acid Composition on Adipose and Systemic Metabolic-inflammatory Responses

Study Overview
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Brief Summary
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Cardiometabolic disorders are a leading cause of death worldwide. Replacing saturated fatty acids (SFA) with unsaturated fatty acids is recommended as a way of lowering cardiometabolic disease risk. Consuming a diet rich in SFA may lead to a greater metabolic-inflammatory response in white adipose tissue during the fasting state, when compared to eating a diet rich in monounsaturated fatty acids (MUFA). Since individuals spend most of the day in the fed (or postprandial) state, it is important to see how different types of dietary fatty acids affect postprandial white adipose tissue and systemic metabolic-inflammatory responses. This study will investigate the effect of a SFA-rich meal on markers of white adipose tissue and systemic metabolic-inflammation, compared to a MUFA-rich meal in overweight adults. In a randomised, single blind controlled, cross-over manner participants will consume either a SFA- or MUFA-rich meal and sequential blood and white adipose tissue samples will be collected before and until 6 hours postprandially.

Official Title
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Impact of High-fat Meals Varying in Fatty Acid Composition on Adipose and Systemic Metabolic-inflammatory Responses: a Randomized Controlled Postprandial Study

Conditions
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Inflammation, Obesity, Inflammatory Response, Cardiovascular Diseases, Overweight

Intervention / Treatment
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* Dietary Supplement: SFA-Rich Meal
* Dietary Supplement: MUFA-Rich Meal


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-50 years BMI = 25-40 kg/m2 Male or Female Waist circumference >94 cm (men) and >80cm (women)* Physically active (> 3 x 30 min moderate intensity exercise per week) Systolic blood pressure < 160 mmHg and diastolic blood pressure < 100 mmHg No cardiometabolic (e.g. heart disease, high blood pressure, type 2 diabetes) or inflammatory illness NOTE: If waist circumference falls below 94 cm for men or 80cm for women but BMI is >25 kg/m2 volunteers may still be recruited at the PI's discretion. Exclusion Criteria: Smoker Previous diagnosis of anaemia Women who are pregnant or lactating Taking medication known to interfere with study outcomes (e.g. treatment for hyperlidaemia, hypertension, inflammation or hypercoagulation) or prescribed antibiotics within the last 3 months Taking nutritional supplements known to interfere with study outcomes (e.g. fish oil or evening primrose oil) Unstable weight history (>3 kg loss or gain in the previous 3 months) An allergy to lidocaine Those with known or suspected food intolerances, allergies or hypersensitivity to any components of the meal (e.g. lactose/wheat intolerance) Alcohol consumption >28 units per week for a man or >21 units per week for a woman Any other unusual medical history or diet and lifestyle habits or practices that would preclude volunteers from participating in a dietary intervention or metabolic study Parallel participation in another intervention study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

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 |
| --- | --- |
| Experimental: SFA-Rich Meal<br>Participants will consume a SFA-rich test meal (75g test fat) and sequential blood and white adipose tissue samples will be collected | Dietary Supplement: SFA-Rich Meal<br>* Saturated fatty acid-rich test meal, containing 75g test fat<br>|
| Experimental: MUFA-Rich Meal<br>Participants will consume a MUFA-rich test meal (75g test fat) and sequential blood and white adipose tissue samples will be collected | Dietary Supplement: MUFA-Rich Meal<br>* Monounsaturated fatty acid-rich test meal, containing 75g test fat<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Protein expression (content and phosphorylation) of key markers of metabolic inflammation in white adipose tissue (for example assessment of NFKB/IKBa total protein and phosphorylation by western blot analysis) | This will be assessed following the collection of white adipose tissue samples across the postprandial period | White adipose tissue samples will be collected at -0.5 (fasted), 1, 4 and 6 hours postprandially | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systemic Markers of Inflammation (for example TNFa and IL-6 concentrations, determined using an ELISA) | This will be assessed following the collection of blood samples | Blood samples will be collected at -0.5 (fasted) until 6 hours postprandially | 
| Gene expression of key markers of metabolic inflammation in white adipose tissue | This will be assessed following the collection of white adipose tissue samples | White adipose tissue samples will be collected at -0.5 (fasted), 1, 4 and 6 hours postprandially | 
| Characterisation of immune cell populations (monocyte subsets) from peripheral blood mononuclear cells (measured using flow cytometry analysis) | Assessed following the collection of blood samples | Blood samples will be collected at -0.5 (fasted) and 4 hours postprandially | 
| Serum Markers of Insulin Resistance | Assessed following the collection of blood samples | Blood samples will be collected at -0.5 (fasted) until 6 hours postprandially | 
| Serum Lipid Profile (primarily triacylglycerol and non-esterified fatty acid concentrations, measured using a spectrophotometric assay) | Assessed following the collection of blood samples | Blood samples will be collected at -0.5 (fasted) until 6 hours postprandially |