Originally Answered: Dad has poorly controlled T2DM, and unwilling to make change..?
Thank you for sharing this, and I am sorry you have to go through this.
Your dad is a classic diabetic in denial. Maybe he feels he can continue to pretend he doesn't have a very serious, incurable condition, because the effects of high blood sugars are not immediate. But while he might not have any obvious symptoms at the moment, his blood sugars are going to kill him sooner rather than later. An A1C of 13% means that his blood sugar is well above the level at which organ damage occurs. It means that 24 hours a day, he is damaging ALL his blood vessels, his heart, his kidneys, basically all the organs in his body. Blood sugars that high, 24 hours a day, mean that the classic diabetes complications are guaranteed. Like kidney disease, limb amputation, blindness, heart attacks and death, sooner rather than later.
What to eat if you don't eat carbs that are going to send up your blood sugar and kill you eventually? Lots of things! Protein, non-starchy veggies, cheese, eggs, butter, nuts. Maybe slightly harder on an Asian diet as virtually all South Asian dishes are high in carb. But I have had wonderful low carb options at South Asian restaurants by sticking to tandoori-style meats with fresh salad. Yes of course it would be nice to have some naan alongside but I prefer having my eyes, kidneys and heart in good working order. And btw, while I know you are trying to be helpful by suggesting whole grains and brown rice, there is actually no difference from a blood sugar point of view. Brown rice turns 100% to sugar, exactly like white rice, so from a diabetes management point of view, is as 'bad' as white rice.
I probably don't have to tell you this but there is NO herbal remedy out there that will work for diabetes. There is only one thing that is guaranteed to lower blood sugar, and that is insulin. I understand that many people are scared at the idea of dealing with needles but actually, life on insulin makes diabetes much easier to manage. I have to be on insulin as I am a Type 1 and my pancreas does not produce any insulin. But when I compare my routine to Type 2s who are on diet/exercise alone, I know I have a lot more flexibility because I am able to cover the carbs with insulin. It means I can eat more carbs than a Type 2 not on insulin.
I honestly don't know what to do about your father's diabetic denial. For me, I never went through that phase of denial because I was diagnosed in very dramatic circumstances. I spent a week in hospital including 24 hours in intensive care with tubes coming out of every part of my body. I still have the needle marks as a souvenir. That brought home to me how serious diabetes is and how it can kill. I don't know what it will take to bring that home to your dad. Maybe show him newspaper stories about people who have suffered greatly because they didn't take care of their diabetes? He needs to make the connection between what he puts in his mouth, and the state of being blind, attached to a dialysis machine, and without any hands and legs. At the moment he is refusing to make that connection - but if he continues the way he is going, that's going to become sad reality sooner rather than later.