From the research in this group, compared with the normal diet group, the high-fat and high-calorie diet group had hyperlipidemia and inflammatory factors such as TNF-α increased.But after 20 weeks of observation, the animals did not develop colorectal cancer,which suggested that only high-fat, high-calorie diet will not cause colorectal tumor for a short period of time. This evidence concerns the gene TNF and hyperlipidemia.