Diet is responsible for about one third of the cancers. Dietary fiber, energy intake, fat and consumption of fruits and vegetables play an important role in different cancers. The regional Mexican diet is characterized as being high in dietary fiber, high in fat and energy but very low in fruits and vegetables. The diet is high in insoluble fiber and phytate. The objective of this study was to evaluate the composition of the regional diet and relate this composition to the incidence of colon cancer in the northern region of México. Two traditional diets, one higher in fruits and vegetables, but both high in fat and dietary fiber were evaluated. A mathematical expression showed the typical regional diet to be low in antioxidant nutrients, even though an earlier study showed it to have a tendency to protect against colon cancer. During the years of 1991-1995, Sonora, México reported about 20 cases/ 100,000 inhabitants of colon cancer. This incidence is low compared to other regions and high dietary fiber is thought to be responsible. If antioxidant nutrient intake was elevated, possibly a greater protection could be achieved.