I was diagnosed with Diabetes about 12 years ago in Jun 2009. I was visiting Delhi and was on way to meet my cousin and I got a call from my doctor that my A1C has come back at 7. I made mental note of it and continued the day as if nothing has happened eating lots of sweets at lunch with my cousin. But I knew I will have to do something about it. I weighed around 182 pounds at that time.
After that I came back to US where I stay, I started an aggressive program of walking, bicycling and eating less. Summers in Texas are quite hot, and I figured out if I walk and bicycle in peak heat it will help me with weight loss. In about a year (August 2011), I was down to 144 pounds and my A1C came to 5.9. In between I had done lots of reading about Diabetes and the medications for it, and I felt that it will take lot more discipline to manage Diabetes with medication than with nutrition and exercise.
Also, long term effects of Diabetes medication seemed scary. Even Metformin which is considered the best medicine for Diabetes seems to cause problems in long run. Just recently Dr Peter Attia stopped taking Metformin after 9 years because long term use seem to cause some muscle weakness (https://medium.com/@PeterAttiaMD/metformin-and-exercise-d%C3%A9j%C3%A0-vu-all-over-again-d738624192c5)
With medication, there can be terrible consequences. For example, just the year before I was diagnosed, a girl in my MBA class shared how her father passed away due to an accident caused by low blood sugar. From my experience, I know it is very hard to have dangerously low blood sugar if you are not on diabetic medication. Now that I am using FreeLibre CGM, I find I never go below 70 mg/dl even when I am doing Time Restricted Fasting(TRF).
Without medication, I have no immediate terrible side effect if I fall off the diabetic management horse due to eating indiscriminately and not exercising for some time. I just have to get back to my discipline in reasonable time. I have gone through such period for up to one to two months few times. And these are characterized by higher than 7 reading on my A1C for those periods.
Over the subsequent years, I gained weight back to about 165 lb. I used to do A1C using FastA1C that Abbott Laboratories discontinued around 2018.