What nutritional deficiency in Kellogg's Corn Flakes necessitates the recommendation of adding fresh fruit or nuts?

Low fiber content

Kellogg's Corn Flakes are explicitly flagged as being low in fiber, which severely limits their ability to promote lasting satiety until the next meal. Since low fiber, combined with low protein, prevents stable blood sugar levels and prolonged fullness, the recommended practical adjustment is to incorporate elements that provide this missing component. Adding fresh fruit, such as berries or apples, or incorporating nuts directly boosts the meal's fiber and protein density, transforming the simple carbohydrate base into a more nutritionally balanced and sustained energy source.