Whole grain bread is great except that this statement does not sound to be very accurate. Sweets and potatoes should not do better than white bread and also the added fat should be distributed all over the body not limited to one area.

I can understand that when you eat more carbs and less fats your stomach gets bigger since it has to keep larger amounts of food in both size and weight. This is because one gram of fat gives 9 calories while a gram of carbohydrate gives only 4.

However, eating plenty of whole grain bread should also enlarge the stomach except that it will reduce the insulin rush problem which causes people to eat more.

Additionally, people who eat whole grain bread are usually more health concerned than the ones who eat white bread. So maybe they do more to improve their fitness than just eating a healthier kind of bread.