Understanding Liver Fat Metabolism: Studies to Understand the Role of Dietary Sugars on Liver Fat Metabolism

Investigating Intra-hepatic Fatty Acid Partitioning and Its Regulation in Man. Studies to Understand the Role of Dietary Nutrients in Liver Fat Metabolism in Relation to Obesity in Man

High levels of fatty substances in the blood increase the risk of developing coronary heart disease and having a heart attack. The investigators know a lot about one of these fatty substances, cholesterol. However, there is another fatty substance in the blood called triglyceride. The investigators do not understand much about what regulates the rate at which the liver produces triglyceride and liberates it into the bloodstream after eating a meal(s). The investigators are developing new techniques to measure these processes in healthy people. Ultimately a deeper understanding of the regulation of this process might lead to the development of new treatments for fat accumulation in the liver and high blood fat levels and related disorders. The present study is an investigation of how these processes relate to various bodily characteristics such as thinness and fatness and the distribution of fat in the body.

The investigators will recruit men and women with no medical condition or relevant drug therapy that affects lipid, glucose or liver metabolism.

Purpose and design:

The investigators are asking the research question: "How does the amount and type of sugars consumed, such as those found in soft drinks, influence postprandial fatty acid and liver fat metabolism?"

It is known that consuming fructose by itself or with glucose can increase plasma triglyceride concentrations and liver fat amounts but it remains unclear how this happens.

To address this research question investigators want to undertake detail physiological studies, in a randomised cross-over study where individuals will be studied twice after the consumption of a single test meal that will contain different amounts of glucose and fructose with the same amount of dietary fat.

Inclusion Criteria:

• Participant is willing and able to give informed consent for participation in the study.
• BMI >19 <35kg/m2
• No medical condition or relevant drug therapy known to affect liver, lipid or glucose metabolism

Exclusion Criteria:

• Age <18 or >65 years
• Body mass index <19 or >35kg/m2
• A blood haemoglobin <120mg/dL
• Any metabolic condition or relevant drug therapy
• People who do not tolerate fructose
• Smoking
• History of alcoholism or a greater than recommended alcohol intake
• Pregnant or nursing mothers
• Women prescribed any contraceptive agent or device including oral contraceptives, hormone replacement therapy (HRT) or who have used these within the last 12 months
• History of severe claustrophobia
• Presence of metallic implants, pacemaker
• Haemorrhagic disorders
• Anticoagulant treatment