My (now 90) year old dad has been T2 for ten years and went lower carb 18 months ago. He sticks to less than 30g a meal, and has mostly dropped bread, potatoes, pasta, rice. This allowed him to come off meds (he was on gliclazide) lose weight and generally look/feel much healthier. He buys 1 person heat up meals for his evening meal but chooses ones with less than 30g carbs. His bgs are now slightly higher than normal (his nurse took him off his last gliclazide tablet without doing an hba1c, which I wasn't impressed by, but honestly his levels are probably better than mine as a T1 diabetic). My brother and he have been isolating from COVID together so my brother has been cooking low carb even meals during lock down (it suits them both as my brother was probably heading for T2 before he went low carb).
The potential issue with your dad is that the insulin may cause hypos if he reduces his carbs without reducing insulin (though at levels that high some reduction in carbs will probably just normalise his levels). Is there anyone living with him to help with the management? (I believe you can get a transmitter to attach to your dad's libre to allow it to send readings to a phone and possibly then to your phone. Look up miao miao????)
Good luck.
May I ask which meals your father has in the evening please as dad is struggling to cook with his arthritis.
No one is living with him, but we go and see him almost every other day.
X