It will be evaluated whether carnitine, a dietary supplement, reduces liver fat and improves metabolism in individuals who have a high concentration of fat within their liver. Participants will be given either Carnitine or placebo, together with a meal replacement milkshake twice daily for 6 months.

NAFLD occurs when too much fat accumulates in liver tissue. This can, over time, cause inflammation and scarring of the liver, eventually leading to chronic liver disease and cirrhosis. It is strongly associated with diabetes and obesity, both of which are endemic in Western societies.

Carnitine enables cells in the body to use fat as a fuel, and recent studies have suggested that carnitine supplementation may reduce liver triglyceride content. Muscle and liver are the major sites in the body which coordinate glucose and fat metabolism. As well as assessing the effect of carnitine supplementation on liver fat, its effect on metabolic processes within these tissues will also be measured

Inclusion Criteria:

• Elevated liver fat on screening abdominal ultrasound
• Capable of providing informed consent
• Non-vegetarian diet
• BMI <40 kg/m2
• Weekly ethanol consumption <21 units/week
• Negative non-invasive liver screen, including Hepatitis B and C serology, liver autoantibodies, transferrin saturation, α1-antitrypsin levels.

Exclusion Criteria:

• Known history of cardiovascular disease
• Known diabetes mellitus
• Known psychiatric comorbidity
• Chronic kidney disease
• Surgery within 6 months prior to start of study
• Exposure to drugs known to influence hepatic steatosis (including steroids, statins, omega-3-fatty acids)
• Current smokers
• Contraindications to magnetic resonance scanning, including implanted ferrous material (implantable pacemakers or defibrillators), metallic ocular foreign bodies, ferromagnetic aneurysm clips or severe claustrophobia.