Is there any reason why I shouldn't be able to do IF while breastfeeding? I plan on having a seven hour window to start and I still plan to eat 1800-2000 calories a day. A dip in my milk supply wouldn't kill my son; he nurses a lot but it's mainly a comfort thing at 15 months.
I'd think as long as you're getting adequate calorie intake it wouldn't be a problem when you get those calories. And since your little one is 15 months you're right in thinking a dip in supply probably wouldn't affect him too much.