Hi fungirl.
From what I understand about Sommersizing, it seems to combine alot of diferent diet ideas which I think would complicate it. I think it really limits your caloric intake. This can lead to frustration and binging. If it works for you, fine. If you are wondering if there is something better, I think so. In Canada (I see your from Edmonton) The G.I. Diet is quite popular and is a bestseller in bookstores. I am amazed at how simple, effective and do-able this program is. It's not a big book - $10.00 paperback. Easy to read and figure out. You may want to check out their website at gidiet.com
There's a lot of different "plays" you can make to get to the goal. Don't give up.