Body fatness does not directly indicate whether one is suffering from cancer or not, but needs to be combined with other manifestations and examinations for diagnosis. Body fatness may be caused by excessive energy intake and insufficient exercise, resulting in accumulation of fat in the body, and it may also be caused by diseases, such as endocrine disorders, hypothyroidism and so on, which can also cause body fatness. Therefore, body fatness can not determine whether cancer, for some cancer patients, in order to help the recovery of the disease, increase nutritional supplementation, not only will not make weight loss, but also make weight gain. Therefore, it is not possible to tell whether there is cancer or not just by gaining weight, and it is necessary to improve the relevant auxiliary examinations to make a clear diagnosis.