Rationale: Excessive fat in the liver, in absence of high alcohol consumption, is diagnosed as nonalcoholic fatty liver (NAFL). NAFL prevalence is as high as 50-70% in obese people and is associated with impairments in metabolic health, e.g. insulin resistance. Not only the amount, but also the composition of the fat stored in the liver appears to be linked to health outcome measures, such as insulin resistance, but this evidence comes mainly from animal studies. Since fat composition has been linked to health outcome measures, it is important to understand what determines the fatty acid composition of liver fat. De novo lipogenesis (DNL) and adipose tissue fat composition are factors that could determine liver fat composition. Since the end product of DNL are saturated fatty acids and as the majority of fatty acids in the liver originate from adipose tissue, both may influence hepatic fatty acid composition profoundly. Up to now, associations between hepatic fatty acid composition, DNL and adipose tissue fatty acid composition have never been determined in the same study.