Brown bread is actually no more or less healthy than white bread, as both breads have different nutritional values that are equally beneficial — while brown bread contains wholemeal, white bread is low in fat and contains magnesium, iron and calcium. Furthermore, white bread, per slice, is only 1 calorie higher than brown bread.
White bread is often incorrectly assumed to be full of sugar, but there is actually no added sugar in bread making regardless of whether the loaf is brown or white. Natural sugars do form in the bread — fructose and maltose — during fermentation, which translates into around 1 or 2 grams of sugar per slice once baked.
Another common misconception is that brown bread is better for children than white bread. White bread actually contains much more calcium than brown bread, which is especially important in a child's development. Brown or wholemeal bread tends to contain around 37 mg of calcium per slice, with white bread having almost double the amount at 62 mg per slice.
White bread also contains less fat than brown bread, although the amount of fat found in any kind of bread is extremely low, meaning bread would have to be eaten in abnormal quantities in order to seriously impact diet. What goes on the bread is normally the main source of fat, such as butter or other spreads.