How Can You Lose Weight Breastfeeding If You Must Stay On A Diet To Produce Adequate Milk?

I’m a first timer debating between breastfeeding/bottle feeding and would like to know how it is still possible for a breastfeeding mother to lose weight while being on a diet to produce milk?
I heard it can burn 500 calories a day to breastfeed, but I also heard you have to consume more calories in order to produce breastmilk?
Just an honest question, if anyone has experience with this I need help! = )

In Your Opinion What Baby Care Items Are A Must Have For A New Born?

i have a daughter but had gotten rid of all of her baby stuff so now i have to start over from scratch. the baby will be here in 3 months and i am getting everything i need next week out of income tax. i already have a crib, highchair, walker, and playpen but that is it. i even have to get clothes etc. what items do you recommend that you cannot go without?