Originally Posted by grapefruitisgrody
I don't want to be confrontational, but I don't buy that. My DH was a vegetarian (cheese and eggs, no milk) for about 10 years and now he eats everything. He had that same worry, but it was unfounded.
You'll get a very upset stomach. If you keep eating it though, then you will be able to continue to eat it and your body will get used to it again and develop the enzyme. I had to stop eating dairy by my doctor's orders for three months and when I started again i didn't feel so well but after about a week I felt better.
It really depends on your body chemistry and for how long you quit eating meat and dairy.
However, I should note, that most humans are not born with the enzyme to digest cow's milk and we develop it as we eat milk products in our early childhood.