Hi Carey,
I think any area of our bodies that are imbalanced contribute to IC. Be it weight (something you can see) to mentally.  A broad range of imbalances exist (many pieces of the pie).  Our bodies will do what they need to do as we become more balanced.
It has been my experience that one will lose weight - just due to the nature of the diet.  Then, as your body heals and you can add more foods - your weight will adjust to a "normal" for you.
My understanding is that gaining or losing weight is not the focus on getting better - it is correcting the imbalances in the body.
Hope this helps
Breis

I was on the brink of being "overweight" when I first got IC - I wasn't quite there, but I was on the line, so to speak.  Before discovering Dr. B and this treatment, I lost about 25 pounds just because everything I had read so much about food affecting IC so I was super scared to eat anything, and I was in so much pain that food wasn't a top priority for me.  I was in way too much pain to be hungry.  I've been on the diet for over two years now (now on List 4), and I don't watch my fat intake or anything like that... I love butter, and I'm never concerned about fat content.  But I'm still a healthy weight.  Have gained only about 10 pounds back since starting treatment.  It is my understanding that when our bodies are in balance and we are eating properly, the weight will balance itself out.  In her dissertation, there is a case study about a woman who is overweight, and Dr. B writes about the specific imbalance with that patient.  I definitely think weight issues are a concern of balance.  As you heal and your body balances, the weight should take care of itself.  That is how I understand the weight issue, and it was the case for me.

I also wanted to add that from my experience, even though I'm only 15-20 pounds lighter than when first getting IC, the weight I do have is proportioned differently throughout my body as I've gotten healthier.  I used to be a size large or XL.  I'm now a small or medium.  The weight has seemed to shifted, so the proportions are different.  Dr. B had told me this would happen, and it is true.  I've had times where the number on the scale stays the same, but all of a sudden, all of my shirts are WAY too big. Logic would say that I lost weight, but in reality, it has shifted to a healthier proportion.  Dr. B says this is a good thing.