growstuff
I agree with Fleurpepper. I've been T2 diabetic for over 30 years and usually control it well with diet and some medication. I drink semi-skimmed milk whenever I want.
Milk contains lactose, which is a sugar, but it's not particularly high carb and is fine if consumed in moderation. If you choose a substitute milk, choose one of the "no sugar" ones. I do occasionally drink almond milk, but I don't particularly like it.
Losing a bit of weight is always a good idea with T2 diabetes, so his first priority should be to cut out cakes, biscuits and sugary items. Eat starchy carbs in moderation. Personally, I hardly ever eat bread, pasta, rice, pastry, rice, potatoes, cereals, etc. I compensate by eating more protein and healthy fats than usually recommended.
And not all carbs are the same. You need to read up about the GI index (Glycemic index). For instance, new potatoes have a lot less starch (= carbs that quickly turn into sugar) that older ones, like baked potatoes. Basmati rice has much less than risotto rice, especially if you wash it well first. Starch in pasta can be reduced a lot if you wash pasta well in cold water after it is cooked al dente, then re-heated, etc. etc.
GI control is the key, as well as cutting out sugar, in drinks and foods, including all the hidden ones (as in take away curries, etc).