I just started the Take Shape for Life program. I'm on Day 2 of eating 5 Medifast meal replacements and 1 Lean and Green meal daily. So far I've been pleasantly surprised: although my daily calorie count is extremely low, I'm not much more hungry than I normally am in a day (and yes, I'm pretty much ravenous every single day).
One thing that's helping is something I learned recently from a Health Coach, Shelley Churchill. It's the concept of primary and secondary foods, courtesy of the Institute for Integrative Nutrition. The primary foods of a person's life, according to IIN, are not food at all: they are relationships, faith, and meaningful activities.
Now, whether you believe that or not, what I know for sure (Thanks, Oprah!) is that the more I focus on the intangibles of life, the less I worry about food. As I indulge my senses, deepen my relationships, pray, and do meaningful work, I am less concerned about what goes in my mouth. And that has made a huge difference for me in this program thus far!