If you do plateau [in your weight loss], check that you're sticking to your plan and whether your goal is unrealistic. The ongoing National Weight Control Registry in America is the largest study of long term successful weight loss ... It finds that people who manage to keep weight off eat breakfast, weigh themselves once a week, watch less than 10 hours of television a week and exercise about an hour a day. If you do all of those things as well as cut your calorie intake, you won't need to measure if your diet is working or not. You'll know that it is.
At least I eat breakfast.