White flour is a processed and refined carbohydrate that have been stripped of fiber. The lack of fiber leads to overeating and the feeling of less satisfied.
How many times have you had more than a few cookies, and did not feel full?
Cookies are a double dose of whammy because it is white flour combined with sugar. Would you rather pass on a cookie, or run 60 minutes on a treadmill?
Losing weight does not have to be harder than it is. Watch what you eat, and eat in moderation.