The findings suggest that fatty liver disease - a by-product of the recent rise in obesity levels - may be prevented by switching to a low-glycaemic-index diet.
For the study, the researchers used mice to investigate the effects of diet on the development of a fatty liver.
One group of mice was fed a high-glycaemic diet consisting of a type of corn starch that is digested quickly, while a second group was fed a low-glycaemic diet of slow-digesting corn starch.
Both diets were equal in total calories, fat, protein and carbohydrate. After six months, the researchers assessed the mice and found that both groups of mice were the same weight.
But the mice fed on the high-glycaemic diet were found to have twice the normal amount of fat in their bodies, blood and livers.
Lead researcher Dr David Ludwigan, an endocrinologist from Harvard Medical School, said: 'Our research creates a very strong argument that a high-glycaemic-index diet causes, and a low-glycaemic-index diet prevents, fatty liver in humans.
'When sugar melts out of high-glycaemic-index food, it drives up the production of insulin which tells the body to make and store fat.
'Nowhere is this message felt more strongly than in the liver, as the pancreas directs insulin directly into the liver.'
Low-fat diets are currently the standard treatment for fatty liver disease, but many children with fatty liver don't respond to them, said Dr Ludwigan.
'We think it is a misconception that the fat you've eaten goes into the liver,' he added.
If left untreated, fatty liver disease can progress to hepatitis and, in some cases, liver failure.Comment below and tell us what you think