The researchers studied how different diets affect the liver in rats. They looked at how low protein, high sugar, or a combination of both impacted liver function. They found that low protein led to increased sorbitol dehydrogenase activity, while high sugar increased superoxide radical formation in the liver. The most significant changes were seen in rats on a low-protein, high-sugar diet, with elevated sorbitol dehydrogenase activity, increased superoxide radical generation, and higher levels of triglycerides in the liver.