I am still nursing my 13 month old twice/day. I gained I think 60 while pregnancy and am below my pre-pregnancy weight.
The trick for me was exercise (light exercise, I walked and so light yoga) once I was able to a certain extent - remember we are burning a LOT of calories with the breastfeeding.
Hydration is right - that's the big key.
AND remember, cutting calories or adding them in, is NOT a huge change in our diets. When my doctor told me to increas by 300-500 calories while pregnant, I just ate evertyhign I wanted all the time. What I didn't realize until she told me I was WAY over was that a cup of apple juice or milk is an easy 110 calories right there.
My point is: even the extra calories we are instructed to eat while breastfeeding are not a lot over what we might normally consume.
My milk only dropped a bit when I stopped drinking water like a fish. Drink more water, I got more milk. (and for stress I took some fenugreek - at least psychologically I felt liek I was getting more milk until i started realizing it was water I needed)
*OH AND STRESS* It's a ridiculous situation, stress reduces milk supply, AND reduced milk supply causes us stress. Bad cycle to get in to.
I am sorry about the gas! For me, I was too lazy about burping her and that's where my kids gas came from. I ate peanut butter, milk, onions etc all the way through my pregnancy and still because there are no allergies in my family to that so I wasn't worried about passing it on.
Anyway, that's my story :)
I was 164 when I came home from the hospital and I'm 104 now and still breastfeeding but not dieting.
(I eat for my blood type - have you heard of that? I like it because it's not a diet... just helps me be healthy)