I've lost quite a few pounds (see below), and eating like this does help.
I always remain static if I eat the same calories week in and out. (I'm very regimented, so I hardly cheat). Now, I have one special cheat food of 200 calories that I use to bump up 2 days a week, plus a 300 calorie energy bar, for long run days, as I am now in such good shape, I'm training for the Disney World Half Marathon.
I don't do weight watchers, but I do count calories. I don't want to flame JMD, but there are beginning to be scientific studies on this. As well as studies pointing to the benefits of "slow behaviors." Nutrition is not just a matter of the equation [eat X <burn X=results] simply because the algorithm for "burning" hasn't really been deciphered yet. Reports have always been inconsistent, and the science is always changing.
An example is this current research telling us that eating little meals througout the day stokes your metabolism, and makes it work faster and harder, as opposed to 3 large meals, resulting in greater weight loss in an extended period of time:
http://www.prevention.com/article/0,5778,s1-4-88-279-3838-1,00.html?
Another example is the slow walking news:
http://walking.about.com/od/weightloss/a/slowwalk0605.htm
Which is a series of new findings that walking at a snails pace can work just as many calories as walking briskly. The point is that your body has to work harder if things are abnormal. Walking slowly causes that change, with minimal change to your joints.
To say that one thing or another "works" or "doesn't work" is simply to do a disservice to yourself and others.
In the field of human nutrition, the bars and standards will always be changing.
I can say that alternating caloric intake, as well as alternating exercise days has helped my overall weight loss.
Although it is true that X calories must be used to lose a pound, it is all an expenditure of energy. To say how fast or slow any one human being's metabolism is moving is simply not feasable at this point in time.
-Tina.