Just like white rice, white bread has refined carbohydrates, which basically tricks the body to start digesting these foods like they were more sugary foods. Anything with refined carbs, which is any product made from white flour, can affect how you control your glucose your levels. Whole grains are always the better option, mainly because they have higher amounts of fiber and cause a slower rise in blood sugar.

But, be warned:

Even the best whole-grain breads can affect blood glucose levels. So, when you are replacing with these, make sure that you are limiting your portions. Try to stick to 1/2 to 3/4 cups of grains or 1 slice of bread.