Here are a couple of meal suggestions:
Lean roast, roasted carrots, roasted potatoes, butter beans, fresh strawberries for dessert
Baked chicken breasts, brown rice seasoned with garlic, onions, thyme, tomato steaks, (thick sliced tomatoes with cheese on top)
Spag with meat balls, garlic bread

If all else fails, call his wife and ask her what he eats. Every diabetic is different in how we process carbs, and in which carbs are best for us. So what will work for me, may not work for him. Don’t be afraid to ask, even if you have to ask him. Good luck.

Spag and meatballs is fine, just use a whole wheat pasta. Plus it is carbs that have to be counted. He will know how much he can eat. Diabetics are not nearly as limited as we were in the ‘dark ages’ of even 10 years ago.

Nellie is correct, diabetics can eat meals like everyone else. The problem with that is that carbs break down differently for us, and certain ones cause sugar spikes. For example take a slice of bread, if we eat plain white bread we will spike faster and then drop faster then if we ate a slice of whole grain wheat bread. So, technically we can eat anything, but actually we can’t if we want to really control our sugars. And if your brother in law is controlled by diet alone, then he really needs to watch which carbs he eats to avoids these spikes that wreck havoc on us.
References :
Retired Chef was happens to be Type 2 diabetic