Milk!

Hi @Derbyshire Boy,
Lots of variables to consider like:
what insulin does your son-in-law take and in what doses ?
What Carb to insulin ratios and is he talking about cow's milk on its own ? Or as part of say, breakfast?
Also skim, or low fat milk or full cream and in what quantity ?
And is he comparing his BSL spikes to your BSL with intake of milk or comparing to someone/something else ?

Sometimes we just can't compare like-to-like. For those of us with T2/Pre D it could just boil down to how insulin resistant we are and I suspect that for those with T1 the individual response differs, too.

I'm lactose intolerant, but I get very different readings depending on which dairy product I have, low or no fat milk products spike me really high, full fat dairy, I only get a small spike. Then again, if I have butter or butter dairy products, my body reacts violently and is similar to an allergy, then again, I eat full fat Greek yogurt, and my levels don't move!
With low fat, no fat, the amount of carbs is higher so my intolerance is higher. I react to if not most carbs, sugars anything with ose at the end of the scientific name!
Most dairy products such as butter, cream, cheese are more concentrated, and the more concentrated the effect increases, but I just don't put this type of dairy, any near my mouth, other than for experimental purposes.
There are many reasons for how dairy effects you, in the short term or long term, the amount of natural fats, protein in dairy is important to get the right balance in your diet, the more intolerant you are or insulin resistance, or how it effects any other conditions, will vary individually.
Because of my intolerance, I have asked how my calcium levels are in normal range.
I couldn't get an answer, much the same to why because my abhorrence of cooked greens doesn't affect my health and is better off without.
My being in ketosis for the last four years has increased my health dramatically, it's healthy for me, on top of all my intolerance to certain foods, my diet is limited, but because of not eating those intolerant foods, my life has changed.
Getting the right balance is important, finding those foods, which effects your diabetes is crucial to your future health, that is why, you need to experiment, record and eat to your meter!