I was someone who lost weight BFing but i do have friends who didn't lose much and some of them lost it quite quickly after they weaned so it probably depends on the person. I definitely had one friend who saw a dietician who said that the hunger can't be controlled but what you eat can, so she was supposed to eat 3 normal meals and 3 snacks and if she felt hungry in between she could anything she wanted so long as it was fruit or veggies. She was an afternoon cream-caker so that did make a difference to her. The dietician had her keep a food diary to see she was actually choosing less useful options first though and she did say that for some women they can eat exactly the amount of food their body needs to be healthy and BF and the body just doesn't let go of the extra weight, so if you know you're eating well and it isn't making any difference then it's probably down to your individual body type.

Michelle71 it might be worth having your thyroid levels checked. Moderate weight gain can be a sign of not enough thyroxine and women with hypothyroidism like mine (Hashimotos) usually lose or gain very little weight when pregnant because the natural hormones of pregnancy supress the immune response which is interfering with the thyroxine production. I gained 6kg all up from 34wks onwards (nothing before then) and lost it all on DD's birthday. It might well be just what your body does, but it's worth getting checked.

Bx