The purpose of this study is to investigate whether substituting saturated fats with polyunsaturated fats reduces fatty liver and improves insulin action and other metabolic variables in abdominally obese subjects

Specific goals:

1. Investigate if substituting saturated fats with polyunsaturated fats reduces steatosis and improves hepatic and/or peripheral insulin action in abdominally obese subjects with type 2 diabetes
2. Investigate if changes of lipogenic enzymes in response to dietary fat intervention are associated with changes in hepatic/peripheral insulin sensitivity or liver fat content
3. Investigate potential mechanism of the effects of dietary fatty acids; e.g. gene expression and lipogenic enzyme activity

Inclusion Criteria:

• abdominal obese subjects with or without type 2 diabetes
• sagittal abdominal diameter >25cm

Exclusion Criteria:

• insulin treatment
• history of serious cardiovascular events
• morbid obesity
• claustrophobia (relative criterion)