> What you do is sensitize them earlier. The open question is:
>would defering their exposure have any positive effect on whether they
>become allergic to the food (I don't think so) or to what degree their
>symptoms will develop (possibly, but I'm still doubtful).

I do believe that in the realm of sensitivities (not allergies) different
degrees of exposure do cause different degrees of sensitivity.  I've
noticed a build-up effect in myself.  Eating more dairy causes more
fatigue/depression.  But if I avoid it for several months, I can have
something dairy once or twice, without noticable problems.  If I keep it up
- something dairy every two days - in only a couple of weeks I'm tired and
depressed.