I was diagnosed with diabetes at the end of September by an endocrinologist. She told me I had type 2, but I tend to doubt her, since I am 18 and non-obese. She told me just to not eat high carbohydrate meals and referred me to a dietician. I have a blood sugar meter and have been testing. My fasting blood sugars are usually between 100 and 130 mg/dl [5.6 and 7.2 mmol/L]. During the day, I can’t get below 200 mg/dl [11.1 mmol/L], even if I don’t eat the second I wake up and I often have been getting readings of HI, which is over 600 mg/dl [33.3 mmol/L] on my meter. I constantly feel fatigued, thirsty, and have blurry vision. I have vomited a few times and have to go to the bathroom every 15 minutes, it seems. To me, these seem like all the symptoms of high blood sugar. I have not been told to test for ketones. I have also lost 10 pounds in the last three weeks. I see my endocrinologist again next week, but have several questions:

Should I be on insulin?
What can I do, without insulin, to get my blood sugar down when I am seeing HI, or even 300 mg/dl [16.7 mmol/L], which I see far more frequently than I should?
How come my blood sugar goes up the second I wake up, even if I don’t eat, and how come it goes down at night?
I have been reading your wonderful site extensively and have read about LADA, MODY, and the honeymoon stage. Do any of these seem more probably than type 2 to you?

I agree with you that I would be suspicious of type 1 diabetes, based on what you have relayed. If your endocrinologist primarily treats adults, there often is a bit of “referral bias.” This means that, if the physician more commonly sees people with type 2 diabetes, they are more likely to suspect type 2 diabetes. Pediatric endocrinologists, I think, have more referral bias for type 1 diabetes. Depending on your family history, you might have one of the rarer forms of diabetes called MODY. Special pancreatic antibody testing can be done to more easily help distinguish type 1 diabetes.

So, to answer your questions:

Based on what you have relayed now, I think you should be on insulin. I think you should also check your urine for ketones if your blood glucose is more than 240 mg/dL [13.3 mmol/L]. If you have ketones, you almost certainly have type 1 diabetes which requires insulin.
Very careful attention to meal planning and increased exercise and staying very well hydrated can try to keep your glucose levels in check. But, if you have type 1 diabetes, you will require insulin.
Commonly, the glucose level is higher in the morning due to the natural production of hormones and physiologic mechanisms that allow you to “kick start” your day. Such hormones include adrenalin, cortisol, and growth hormone. By the end of the day, you have (presumably) been a bit more active so glucose levels commonly are lower then. If you had a schedule whereby you slept during the day and awoke to work at night, your glucose levels would eventually shift the pattern to accommodate your daily schedule and thus be high at night when you woke up.
See answer #1 above. The “honeymoon stage” is a phase of type 1 diabetes when the pancreas does produce insulin in a better, but typically temporary, fashion.

I’d seek further dialogue with your endocrinologist or seek a second opinion.

DS