Here is a link to a nice article in the New York Timeson the role that exercise can play in achieving and maintaining a lower weight. You might be surprised that they conclude that exercise does not appear to be critical for weight loss (but it is important for weight maintenance).
I think there are two important ways that this fits with Dan’sPlan. First, we recommend a multi-phase approach because weight loss is different than weight maintenance. Second, it is important to remember that there are no magic bullets. Exercise alone is no more the sole solution than is the latest fad diet or nutritional supplement. It is important to eat a variety of foods, to move in a variety of ways, and to get enough rest so you can eat and move to the best of your ability.