There is no way they can tell whether you have type 1.5 or type 2 diabetes from an elevated fasting blood sugar. The only way is to measure your insulin levels, both fasting and as part of an oral glucose tolerance test. If you are already lean, type 1.5 is a real possibility. This is discussed in the thread you referred to, so please read it, and be sure to ask your docs how they know it is type 2 vs. 1.5 (both are ADULT onset, but while type 2 is caused by insulin resistance, type 1.5 is caused by insulin undersecretion). Get yourself a copy of Dr. Bernstein's Diabetes Solution. I control my diabetes *very well* on it.