How young is too young to put your foot down about food?

My son is 18 months and I have absolutely had it with fighting over meals. He was a great eater, I mean really great, until one day a few months ago he morphed into this monster toddler; now there is nothing he will eat consistently other than bread and cheese. At first I was giving in and offering something else because he is/was still so young, and he’s also very low on the weight charts so his weight has always been a source of anxiety for me. However, this is not sustainable and the situation is only getting worse. This can not continue. I am very ready to start the “this is what we’re eating, take it or leave it” policy but part of me feels like he’s still too little for him to really understand. On the other hand, he obviously has the capacity to manipulate us into getting something else, so there’s that. Am I wrong to think it’s time to be done with negotiations? Alternatives that worked for you?They weren’t kidding when they tell you it all happens so fast. One day I had a tiny infant, and the next day I had a toddler beast! Help! via /r/Parenting https://ift.tt/2PSGUdw