No OH is great about it, he is totally on board and understands the research. FIL and MIL FF both their kids and honestly I think they're rejecting the research on BFing because it makes them feel like bad parents. I just want to be prepared at Christmas in case it becomes a discussion again. FIL's argument is that I'm looking at only one source, one paper that supports my position. I need to have several sources that are peer-reviewed to have in my pocket in case I have to defend myself again.
I appreciate the response! I need to look over all the papers, especially the ones for extended BFing as I'm sure that's the next argument (she doesn't need it anymore, you're just coddling her).
Let's face it, your FIL is an academic and people who try to use research to prove you wrong will always find something to challenge you with. As long as you continue to battle against him on his turf (research) you will always lose in his mind. Instead of trying to convince him academically on the benefits of BF it might be more productive to be nonchalant about it.
For example, if he goes off on a rant "research shows that BF is useless blah blah blah..." you can say something like "oh well, LO seems to like it and I'm a little too lazy to muck around with sterilizing bottles." Or play a different card when they start to talk about formula and say something like "we really can't afford formula" or "FIL, I don't eat processed food, so my baby doesn't eat processed food."
Something else that might be effective is to call him out on his need to disprove your parenting choices. You can ask him "why is it so important to you to discredit BF? Didn't you raise your children the way you felt was best? Well this is my baby and just like you raised your children according to your sensibilities we will raise our kids according to ours. I find it fascinating that you go through so much trouble to research BF just so that you can tell me that I'm wrong. What's it to you anyway?" And then laugh as if it's hysterical.
I'll be honest, I've come across a lot of people who think BF is weird or wrong or unnecessary. I've tried to explain the benefits of BF but they don't care to listen, they already know what they know and don't have an open mind to admitting that they don't know anything. In the long run nothing shuts a person up more effectively than just nodding your head, smiling, and ignoring them. With a person like this it's best not to engage in conversation, don't step into the ring at all. Sometimes people just want to hear themselves talk - let them. You know that you won't be changing your mind about BF and as long as you engage in conversation with him your FIL believes he has a chance of outresearching you. If you just let him talk without bantering he'll just eventually sound like a crazy obsessed person. Just smile and nod and BF your baby lol.
Sorry for the lengthy post, this subject really gets to me.
Not his field, maybe? 
