Why the liver handles fructose differently from glucose
Unlike glucose, which most tissues can take up and use, fructose is metabolized largely in the liver. When fructose intake is high, particularly from added sugars and sweetened drinks, the liver processes it through a pathway that can readily feed de novo lipogenesis, the manufacture of new fat. The resulting fatty acids are packaged into triglycerides.
When this production runs faster than the liver can export triglycerides into the blood, fat can accumulate within liver cells, a feature of non-alcoholic fatty liver disease.
Dose, context, and what the evidence supports
The concern centers on chronically high intakes of added fructose, often alongside excess total calories, rather than the modest fructose found in whole fruit, which comes packaged with fiber and water. Much of the mechanistic detail comes from animal and short-term human studies, and total energy balance and overall diet remain major factors in fatty liver risk.
This is general educational information, not medical advice. Fatty liver disease is a clinical diagnosis, and its evaluation and management belong with a qualified professional.