I just watched a YT video last night with Dr. Boz (Annette Bosworth). She described a subscriber who had been type 2 for 20 years and was quite obese (5'8", 255 lb).

The man followed Dr. Boz's keto program and proceeded to lose 70 lb over the next 8 months. He was still type 2, but his numbers were vastly improved.

The man was 68 years old, so it's never too late to get the weight off. Dr. Boz had to admit that it might be too late to heal the pancreas and insulin resistance, but to give it more time as the damage was incurred over a number of years and wouldn't reverse itself "overnight."