Nursing a 12 month old, menses back at 6 months post-partum.

Has anyone noticed a noticable weight gain more significant while nursing?

Normal weight gain during this time would be maybe 2 or 3 lbs but with nursing the last wfew months have been closer to 7-10lbs and a slower loss of those after the week is over. I have no real diet changes during this time, no general decline in activities.

Anyone else? How do you combat this?