no weight loss Still Diagnosed Chronic Pancreatitis

I am positive I have Chronic Pancreatitis, but why no weight loss. I retain fluid, I can feel this in my extremities. I have almost constant Diarrhea from IBS. I eat like a normal human being when I dont have flare ups, EX: chicken and fish, low fat dairy and skim milk, Every kind of fruits and veggies, once a week chocolate, No fried foods,  No alcohol, No Smoking I cook with Smart Balance everything. So why am I  5'4 and weigh 190lbs.??????? during flare ups of CP I can only manage a liquid diet. I am able to walk for 30 min every day, any more and I can feel the demon in my Pancreas rumbling.  Thanks for your input as it is greatly appreciated.