The artificial, non-saccharide sweetener aspartame, found in diet sodas, is the culprit here. A study has shown it to increase insulin resistance and trigger fatty liver disease, which means there is a buildup of extra fat in the liver cells. Alcohol has also been linked this condition as well. The organ’s job is to process everything people eat and drink, but too much fat will have an effect. The illness can also be brought on by excessive drinking. Alcoholic fatty liver disease is the earliest stage of other drinking-related liver problems. There are usually no symptoms, according to the Liver Foundation.