The primary ingredient in most rye breads is white wheat flour. Most rye breads have less than 1 gram of fiber per slice. In general, rye breads and multi-grain breads are very similar in nutritional content. The color of rye bread does not affect its nutritional content.
Products made out of whole grain rye are healthier in many ways than products made out of whole grain wheat. Substituting rye for wheat may be helpful in weight loss, controlling diabetes and reducing inflammation. However, rye bread is not a product in which rye has been substituted for wheat. Rye bread is wheat bread with rye added for flavor.