Final answer:
True, high-protein diets typically lack protective dietary fiber, which is associated with a decreased risk of various types of cancer, especially colon cancer, due to fiber's role in speeding up waste passage and reducing carcinogen concentration in the colon.
Step-by-step explanation:
The statement about high-protein diets being low in protective dietary fiber is true. Dietary fiber plays a significant role in cancer prevention, particularly concerning colon cancer. High fiber intake is associated with a reduced risk because it accelerates bile acid excretion, speeds up the passage of materials through the colon, and thus dilutes the concentration of potential carcinogens. This means that diets lacking sufficient dietary fiber may not provide the protective effects against certain types of cancer.
In addition to reducing cancer risks, dietary fiber is also linked to lowered rates of coronary heart disease and type 2 diabetes. Health guidelines recommend increasing the intake of fruits, vegetables, whole grains, and legumes, which are all high in fiber, to decrease the risk of various chronic diseases. On the other hand, a high-protein diet focused on animal products may lack sufficient fiber, as these sources are typically low in fiber compared to plant-based foods.