Exploring the Effects of Varying Fat:Carbohydrate Diet Permutations on Gastric Emptying and Metabolic Status Using Human Postprandial Model

The aim of this clinical trial is to investigate the effects of the meals moderated by fat and carbohydrate (CHO) quality along with varying macronutrient distribution (CHO: fat) on gut physiology and metabolic outcomes using the human postprandial model with healthy subjects.

The main question\[s\] it aims to answer are:

1. How does meal composition with different polyunsaturated/saturated (P/S) ratio, glycemic index and macronutrient quantity affect lipemia and glycemia?
2. How does meal composition with different P/S ratio, Glycemic index and macronutrient quantity affect gastric emptying?

The study's objectives will be tested via a randomized, crossover study with 16 diet rotations separated by minimum one week washout period. All recruited subjects will be randomly assigned into 2 groups of 7 each namely HGI and LGI with 9 diet rotations within each group. The study design will be a cross-over trial with the same subjects undergoing all arms of the diet rotations. The subjects will be blinded to the test fats used for each rotation. Body weight measurements will be recorded before each postprandial challenge to minimise weight fluctuations between the test rotations.

Study procedures

1. Oral glucose tolerance test (OGTT) Sessions

   Prior and end of the test meal rotations, subjects will undergo oral glucose tolerance test (OGTT) with a glucose reference drink at 2 random sessions without MRI investigation at Taylor's University or Hospital Cancelor Tuanku Muhriz (HCTM), to get an average value for the plasma glucose and insulin standards for each subject. The glucose reference drink composition will be 50g of anhydrous glucose mixed with 250mL of room temperature water. Blood samples will be collected sequentially at 0, 15, 30, 60, 90,120 and 180 minutes.
2. Test meal sessions

During each postprandial test meal rotations, subjects will consume test meals followed by MRI scans at the MRI center at Hospital Cancelor Tuanku Muhriz(HCTM). For scheduled session, Subjects will be advised to refrain from strenuous physical activity, high calorie or fast-food, supplements and coffee intake for 24 hours preceding each postprandial event. Subjects will be at the clinical center at 7:30 and 8:30a.m, following a 12-hour overnight fast. Upon arrival at the centre,subjects will rest for 10min, followed by body weight, blood pressure and self-monitoring of blood glucose (SBMG) measurements. Subsequently, blood samples will be drawn for metabolic investigations as per study objectives. Sequential postprandial MRI scans before and after test meal intake at 0(fasting), 15, 30, 60, 90, 120, 180, 240 and 300 minutes.

Eligibility Criteria:
Inclusion Criteria:

Healthy subjects, (n=12-14) without history of chronic disease(s) with body mass index (BMI) between 18.5-25.0 kg/m2 and normal fasting blood glucose status \[\<5.4 mmol/L\] will be enrolled into the study.

Exclusion Criteria:

1. Using pharmacotherapy that interferes with lipid and glucose metabolism or gastrointestinal transit (constipating drugs) or on oral contraceptives (women).
2. Underweight body mass index (BMI): \< 18.5 kg/m2
3. With medical history of cardiovascular disease (CVD), Diabetes Mellitus, dyslipidemia and other chronic diseases,
4. acute or chronic gastrointestinal illness
5. If vulnerable to claustrophobia or anxiety
6. Regular alcohol usage
7. On low-calorie diets
8. Smoking