Fructose’s propensity to cause fatty liver is unique among carbohydrates. The fatty liver directly causes insulin resistance setting in motion the vicious cycle of hyperinsulinemia – insulin resistance. Furthermore, this harmful effect of fructose does not require high blood glucose or blood insulin levels to wreak havoc. Further, this fattening effect, because it acts through fatty liver and insulin resistance, cannot be seen in the short term – only in the long term.
Fructose overconsumption directly produces fatty liver, which in turn directly creates insulin resistance. Fructose is five to ten times more likely than glucose to cause fatty liver. This sets off a vicious cycle. Insulin resistance leads to hyperinsulinemia, to ‘overcome’ this resistance. However, this backfires, as the hyperinsulinemia, made worse by the attendant glucose load, leads to further insulin resistance.