Whole grains are an important part of a balanced diet. But being brown does not mean bread is made from whole wheat. Brown bread is often a mixture of white flour and whole-wheat flour with added ingredients for color, such as caramel. In United States and Canada, you can be assured that bread is actually made from whole grain if the label specifies "whole wheat."
Bread made from 100-percent whole-wheat flour contains all the parts of wheat grain, including the bran, germ and endosperm. The bran, or outer layer of the seed, is rich in vitamins and fiber. The germ contains vitamin E, protein and fat. The endosperm, or kernel, contains most of the wheat’s protein and carbohydrate content. During processing, the bran and germ layers are removed, so the ingredients in brown bread are stripped of many nutrients. Even after “enriching,” brown bread contains less fiber and fewer vitamins.
One slice of commercially prepared whole-wheat bread contains 66 calories. The total fat content -- .91 grams -- consists of .2 grams of saturated fat, .2 grams of monounsaturated and 0.3 grams of polyunsaturated fat. Whole-wheat bread contains 12 grams of carbohydrates, 2 grams of each of dietary fiber and sugar. Whole wheat bread contains no cholesterol and 4 grams of protein, according to United States Department of Agriculture national nutrient database. The calorie composition of brown bread varies with the brand and the ingredients used. An example of a slice of generic brown bread contains 118 calories with 4 grams of fat with 1 gram of saturated fat. Brown bread contains 16 grams of carbohydrates, 6 grams of dietary fiber and 1 gram of sugar. The protein content is 6 grams.
Vitamins and Minerals
United States regulations stipulate that white flour must be fortified with B vitamins and iron to replenish the loss during the refining process. Whole-wheat bread, in addition to being rich in B vitamins thiamine, riboflavin, niacin, pantothenic acid and vitamins B-6 and B-12, is a good source of folate, necessary for the prevention of birth defects. Whole-wheat bread also contains vitamins E and A. Nutrition in brown bread depends on the type of flour used and the degree of refinement. On average, whole wheat bread contains up to 300 percent more zinc, 40 percent more iron and more magnesium, manganese and phosphorus than brown bread made with refined flour.
Foods that rate low on the glycemic index have the least effect on your blood sugar levels, which may help with weight loss and diabetes. Whole wheat bread is low on the glycemic index, which means its carbohydrates slowly increase blood sugar levels. This translates to better health and a lowered risk of insulin resistance, obesity and cardiovascular disease. After refining, the carbohydrates remaining in the flour used to make brown bread quickly convert to glucose in the body during digestion.