My husband has type 2 diabetes and drinks enough coffee to drown a herd of elephants. He watches his diet, only 20 gr of carbs per day, and is very thin now, was never fat. Seems like what helps most, the days we go to the gym and work out for at least an hour, stepper machine and lifting weights, that seems to lower his blood sugar the most, better than diet or pills. Type 2 comes to people over, under, over. Over 40, underactive, overweight. He was never really overweight, but following the super low carb diet, that he got from a specialist in the field of diabetes, he has gotten very thin.
I think they seriously need to find a cure for this. This epidemic seems even worse than cancer was in the 80’s.
When my husband got diabetes, he read all about the connection with coffee. It also is true of decaffeinated coffee, so it’s not the caffeine. He never drank coffee, but now does. However, it runs in his family, so I suspect he was pretty much bound to get it. Like your husband, though, his blood sugar responds best to exercising in the gym.