I lost 38kg over about 9 months while breastfeeding (and I still am). TBH, I think you would have to be severely limiting your calories for it to have any impact on milk production - hormones and your baby are going to be what keeps breastfeeding going .

I changed my diet (went from eating mostly crap food to mostly healthy food) and started exercising most days a week. At first I was just walking and doing 10-15 minutes on our exercise bike. Now, I run several times a week (and planning on going in a half marathon in September!), have started attending yoga once a week, and go for the occasional swim/walk/exercise DVD.

HTH - good luck! It's tough juggling exercise with a young bub, but it is most certainly possible .