we're trialling our 2.5yr old on gluten free for sleep and behaviour issues. we noticed a huge difference in her sleep and behaviour until i gave her ski dlite honey buzz yoghurt and she turned back to how she was before . i can't see anywhere where gluten is on the yogurt but wonder if it was that?
I can't give you any advice but it is interesting you say that as DS, also on GF seemed to have a reaction to yoghurt as well. Can't remember the brand, but it was one in the "squeezie" packet with high levels of "live cultures." I put it down to the "cultures" but now I wonder if it was something else in it.
i have now considered fructose intolerance. the more i look into it. the formula she was on had corn syrup solids as the main ingredient and the ngihts she had one in the middle of the night she was way more unsettled so cut that out immedietly
Personally with my kids I avoid yoghurts with artificial ingredients in them and go for an organic, plain natural yoghurt and add a little pureed fruit or raw honey into it for sweetness... the kids love it and it doesn't irritate my son's eczema.
I wouldn't discount the acidity regulators. Lite products often have more of these (eg. higher quantities than the 'regular' brand to make up for taste etc.). These might also not be helping the situation