One would therefore expect vegetarians to have a lower incidence of colorectal cancer than those who eat meat; however, the evidence to support this is not consistent. Whereas US Adventist studies found that vegetarians had a lower risk of colon cancer, a study of British vegetarians found that they had a similar rate of colon cancer to nonvegetarians. It may be that the classification of vegetarian and nonvegetarian is too simple, and vegetarian diets may differ widely in nutrient composition, even in the absence of red meat. This may particularly be the case when comparing vegetarians in different countries. The definition of vegetarian may also differ between studies, with some classifying themselves as vegetarian while still regularly consuming seafood or white meat. It has been suggested that more descriptive vegetarian subtypes need to be used for epidemiological research