Investigating the Effects of a High GI Versus a Low GI Diet on Hepatic Metabolism and Satiety Levels in Healthy Subjects

Investigating the Effects of a High GI Versus a Low GI Diet on Hepatic Metabolism and Satiety Levels in Healthy Subjects

The aim of this study is to investigate the effect of a one week high versus low glycaemic index dietary intervention on hepatic glycogen and lipid levels and blood hormone levels in a two way cross overs study and to see if there is any correlation between this and satiety or appetite.

8 Healthy subject will be scanned the start and end of a 7 day high versus low glycaemic in diet with a 4 week washout between arms. During scan days the hepatic glycogen response to a corresponding high versus low glycaemic index test meal will be measured using 13C Magnetic resonance spectroscopy (MRS) to explore any acute changes in metabolic response. Baseline liver lipid levels will be measured using 1H MRS to explore any long term changes in liver lipid levels.

Blood samples will also be obtained throughout the test day to measure for blood glucose, insulin and blood hormone response. Satiety surveys will also be taken throughout the test day and during the diet week.

The main hypothesis is that a one week calorie matched Glycaemic index varied diet will result in an altered response of liver glycogen levels acutely following a meal and also longer term hepatic liver lipid levels. A secondary hypothesis is that there will also be associated changes in blood sugar and hormone levels and that all these changes will have an effect on satiety levels in subjects.

Inclusion Criteria:

• Male
• Caucasian
• Self-reported non-athletic but healthy: not carrying out strenuous exercise (no high sweat, out of breath, high heart rate activities and less than 2 hours moderate exercise a week), moderate drinkers (less than 3 units a day), no smokers
• Routinely eating 3 meals a day
• Stable weight
• Age ≥ 18 and ≤ 35
• Body mass index (BMI - weight / squared height ) ≥ 20.0 and ≤ 27.0 kg/m2
• Suitable for MRI scanning (e.g., absence of metal implants, infusion pumps and pacemakers) as assessed by the attached MRI safety questionnaire.
• Suitable for blood samples and cannula insertion (e.g., no aversion to needles)
• Willing to follow both prescribed diet plans
• Not taking any concurrent medication

Exclusion Criteria:

• No diabetics or other metabolic disorders (e.g. insulin resistance, thyroid dysfunction)
• No volunteers with liver disease
• No clotting disorders
• No Participation in another nutritional or biomedical trial 3 months before the pre-study examination or during the study.
• No use of any medically or self-prescribed diet from the moment of pre-study examination till the end of the study
• Taking prescription medication or any other drugs that may influence liver function or glucose and energy metabolism.
• Any allergy or food intolerance
• Unsuitable for MR scanning (i.e. have pacemakers and/or medical implants)
• The subject is an employee of Unilever or the site conducting the study.