I know others will have their own opinion based on their own experience but for me here is what I have found:
For reference:
I am newly diagnosed as Type 2 (~1 month) and other than blood sugar my only other diagnosed issues are high triglycerides and a vitamin D deficiency.
Separate from high blood sugar related stuff, my blood pressure and resting heart rate is always perfect whenever tested, and never had any physical outward signs of stress. 10 years ago I had a small kidney stone that passed and didn't know what it was so went to the ER and the pumped me with morphine and ibuprofen and gave me some pretty high doses of ibuprofen to take over a week without instructions. The ibuprofen ended up giving me a mild ulcer that lasted til now though with diet change, more water intake and improved diet over the years I rarely feel it come up. I didn't realize what a high carb & high sugar diet would lead to, though, I should have known as my family blood lineage has a history of diabetes.
The moment I got clued into my blood sugar levels I made a change (no breads, no sugars, no sodas, no fruit juices) but still thought pasta, bottled tomato sauce, rices and some cereals/oatmeal was fine. A week later when the initial clue turned into an actual diagnosis from a fasting level needing a full blood test for A1C and a bunch of other stuff, I dug into research immediately and realized how much I would need to change my diet. I would call my current diet for the past 3-4 weeks very Keto but not 100% as I have yet to meal prep properly or prep my grocery shopping to always have a balanced intake or consistent times of day eating. I've also not yet increased my exercise nor done anything dramatic like intermittent fasting or time eating restrictions. I've not yet taken any prescriptions though my doctor prescribed Metformin and a common statin (for the high tri's and LDL) which if after diet change and exercise haven't taken me most of the way within 1 month I will take to help and then try to work off of with more dedicated efforts. I have also seen an endocrinologist and will try to get lab tests next week for antibodies and c-peptide to make sure it's just Type 2 and not LADA or MODY.
Now onto why I'm replying to this topic:
I finally feel like I confirmed today that stress is an equal factor of my high blood sugar levels as what I've been eating. Other than a high morning level (usually about 180 or a little higher) I've noticed that my average with my current diet and staying calm is in the 160 range and a little lower after I keep myself mentally busy working in the garage or doing something creative, basically when I am either very calm or doing something I enjoy or both. If both it goes under 150 even when it's only been 2 hours after a meal when otherwise levels should go up a little. As a reference, initially at diagnosis and the first 1-2 weeks of checking my levels I was in the 250-300+ range.
I have noticed very consistently other than my morning levels my high levels have always tested while I was at work or as soon as I got home from work (even after not eating for 3-4 hours) - 190, 200 and sometimes 220+ while on weekends when eating is more fluid. I had thought it might be due to big time windows between meals causing my liver to think I needed energy and pump up the glucose but found that introducing small no-carb snacks between lunch & dinner didn't change much. I started paying attention to my stress moods and noting when I was stressed when testing in addition to what I ate & how long before. There was a rough but clear correlation.
Then this morning (Sunday) when I got up I tested at 184. The prior day I tested 5 times and never went above 173 and my average was 163. I had planned to eat breakfast but work reached out to me with an emergency need so I spent the next 3 hours fulfilling a number of requests without any chance to take a break to make a meal. I'm in technology and salaried and during emergencies this is sometimes not a choice. So finally I was able to get a meal and tested myself before eating and it was 198! This was well past the "dawn phenomenon" and seeing as I hadn't eaten anything yet, the most logical testing should have shown a blood sugar level below 184, probably 160 or so (at least for me). Instead it was higher. Then, I had breakfast which included keto bread (so it had some almond flour), eggs, butter, turkey and cheese, and a coffee with half & half and stevia. Between the small amount of carbs (estimate 4-6 grams) and coffee, I should have tested even higher 2 hours later. Nope, it dropped to 164. Meaning, even after eating, once my stress was gone, only then did my levels get to my "good" average range.
This convinced me that stress (at least for me) is a big factor in spiking my levels. It's not the only thing, diet & exercise are still needed, but I now believe if I can alleviate stresses from my day (either handle them better or simply find a way to obliterate them) then I can shave roughly 30 points off my blood sugar levels fairly consistently. I have so far JUST changed my diet fairly dramatically but not yet fully and took myself from 250-300 to the 160's average and if I am right about stress I can get it more consistently 130-150, then added exercise SHOULD get me down to a 110 range average where then, if absolutely needed, something like Metformin might be able to smooth out the spikes and bring my body back to normal insulin sensitivity.