Too much sugar is not only bad for your teeth or liver, but it can harm your liver too. The liver uses fructose (one type of sugar) to create fat. Too much refined sugar and high-fructose corn syrup cause a fatty buildup that can lead to liver disease. Some studies show that sugar can be as damaging to the liver as alcohol, even if you’re not overweight. One more reason to limit foods with added sugars, like soda, pastries, and candy.