PreDiabities. 115/75 most of the time.

Three years back ( April 2018) My hba1c was 6.4 and I didn't know what it meant. I googled it out and got to know it was prediabitic range. I was 92 kg which was slightly overweight and my diet was not that great. Also sedentary life style. After that I started exercising and dieting and reduced my mental stress and improved sleeping habit( All these changes I maintained only few months).Never got blood test again. After three years now ( June 2021) my hba1c is at 6.2. And since 2 years no dieting and no proper exercise. Also weight was more than what it was when hba1c is 6.4. Please help me if I can reduce it naturally. My both parents are above 70 and they do not have diabities. My siblings do not have it. My grand parents didn't have it. In my entire family only younger brother of my father had it and he was overweight and always sedentary also very stressed. I have no blood pressure issues. I almost check daily and it stands at 115/75 most of the time.