The piece of evidence that is not relevant and should be removed or replaced is: "Most people find oatmeal a little bland and so they add sugar, honey, fruit, or nuts."
This statement does not directly support the main argument about the nutritional differences between old-fashioned oats and quick oats, which is the focus of the passage. The other statements are more relevant to the comparison of the nutritional value and cooking processes of the two types of oats.