Kidney cancer patients should be cautious with their diet and there are three types of food they should absolutely avoid:

First, foods high in salt. Kidney cancer patients often suffer from severe kidney dysfunction, leading to edema. Consuming salty foods can increase the body's sodium content, causing sodium retention which is not metabolized in time, exacerbating the swelling.

Second, high-fat foods. Excessive fat can also lead to weight gain, and high body fat can burden the kidneys.

Third, foods high in potassium. With kidney cancer, patients often have inadequate kidney function and produce less urine, leading to high levels of potassium in the body. Consuming foods high in potassium can further increase blood potassium levels. Therefore, it's advisable for kidney cancer patients to avoid fruits and vegetables high in potassium.