I don't think this is correct. Type 1 is an autoimmune disease, it can strike at any age. About 20% of people newly diagnosed with type 1 diabetes are diagnosed over 40 -
https://www.diabetes.org.uk/about_us/news/1-in-5-cases-of-diabetes-diagnosed-in-the-over-40s
@CrankyKat all a hba1c will tell you is what your blood sugar is doing, it doesn't tell you
why it's doing it, so is literally no help in determining type of diabetes. Do you know what your urine is being tested for - have you been give any instructions for it to be first pee of the morning or after a meal etc?
Anyway, there are two tests that can help with determining type of diabetes:
- A cpeptide test. This tests to see what your insulin production is looking like. It can be don as a blood test or as a urine test, but my recollection is there are some specific instructions on the timing of the pee they want! It doesn't give any sort of definitive answer on diabetes type as a honeymooning type 1 will be producing insulin and a type 2 who's pancreas has been exhausted won't be.
- Antibody testing. Type 1 is an autoimmune disease, so they can test to see if you have the antibodies associated with type 1. There are 4 or 5 identified antibodies. The most commonly tested for is GAD. If you are GAD positive you are definitely type 1. But if you are GAD negative that doesn't necessarily mean you aren't type 1. About 25% of type 1s are GAD negative.
So, the testing might not actually give a definitive answer on type of diabetes. Sometimes the clinical picture of your diagnosis gives more of an indication of diabetes type. How were you diagnosed? How long have you been diagnosed with diabetes? It's not unusual for type 2s to have complications, like retinopathy, on diagnosis because they may have had undiagnosed diabetes for years. This is much less common for type 1s as type 1 is an acute onset condition. Had you had significant untried for weight loss pre diagnosis? What were your blood sugar levels on diagnosis (over 20 or 30 would point towards type 1)? Did you have ketones on diagnosis (it's very unusual for a type 2 to have ketones, but 85% of type 1s are diagnosed in DKA)?
How are you currently managing your diabetes? Things that may suggest LADA, rather than type 2, would be inability to achieve blood sugar control with diet, exercise and oral medication and continued untried for weight loss.
You say your consultant is confused by your weight. It should be remembered that you don't have to be fat to be type 2, it is perfectly possible to be normal weigh or slim and still have type 2 diabetes. While being overweight significantly increases the risk of type 2 and the media likes to present it as a disease for fat people, that's just not correct. Other lifestyle factors, like shift work and high stress can increase the risk of type 2, as can things like hormonal imbalances and PCOS, and there is a significant genetic element to type 2 so if you have a family history that could make type 2 more likely no matter what your weight is.