Rye bread is a type of bread made with various proportions of flour from rye grain. It can be light or dark in color, depending on the type of flour used and the addition of coloring agents, and is typically denser than bread made from wheat flour. It is higher in fiber than white bread and is often darker in color and stronger in flavor. Compared to white bread, rye bread has a lower glycemic index, which means it does not cause a spike in blood sugar.