A small amount of fructose, such as the amount found in most vegetables and fruits, is not a bad thing. In fact, there is evidence that a little bit may help your body process glucose properly. However, consuming too much fructose at once seems to overwhelm the body's capacity to process it. The diets of our ancestors contained only very small amounts of fructose. These days, estimates are that about 10% of the modern diet comes from fructose. What happens if I consume too much fructose?
Most of the carbohydrates we eat are made up of chains of glucose. When glucose enters the bloodstream, the body releases insulin to help regulate it. Fructose, on the other hand, is processed in the liver. To greatly simplify the situation: When too much fructose enters the liver, the liver can't process it all fast enough for the body to use as sugar. Instead, it starts making fats from the fructose and sending them off into the bloodstream as triglycerides .