The Food and Nutrition Board of the National Academy of Sciences recommends that people eat no more than 30 percent of their daily calories as fat. Tips to reduce fat in your diet . Specific nutrients and food constituents of fruits, vegetables and whole grain cereals may be anticancer substances when eaten at levels found in a varied diet. Some food constituents and specific nutrients believed to protect against cancer are dietary fiber, phytochemicals, and vitamins A, C and E. Dietary fiber. Dietary fiber is the material from plant cells that the body cannot digest completely.
Dietary fiber is found in vegetables, legumes, fruit and whole-grain cereals, nuts and seeds.
A diet high in fiber and low in fat may reduce the risk of colon and rectal cancers. Fiber provides bulk in the diet, and it helps move food through the intestines and out of the body at regular intervals. It is unclear whether it is total fiber intake or the components of dietary fiber that is beneficial in reducing cancer risks. Evidence suggests that certain compounds in plant food sources, particularly fruits and vegetables, can be cancer fighting. These compounds are called phytochemicals, which is actually a general name for several cancer-fighting substances, such as flavonoids, allylic sulfides and sulforaphanes.