I essentially quit dairy. It did things like make me feel like I was having a heart attack as early as age five. I'll have a reasonable amount now and then and it doesn't bother me mostly. Andrew Weil suggested people with food sensitivities could try gradually reintroducing after stopping and recovering. Sometimes I remember this and try a little and I'm fine. Thing is, I grew up downing pints of milk and such. I guess you can OD on it but you can also tweak your prescription till you get it right.