What can be done to lower your glucose level in your body?

My dad’s glucose of serum is 96 mg/dL, and about 19 months ago, it was 91 mg/dL (which were all based on a fasting test). My dad, 55 years old, wants to know if at risk of getting diabetes. With that said, is he? My dad wants to know what he can do to lower his glucose level, without any means of medication.

he does not need to lower his glucose level, he is within the normal range, just be cautious of his diet, avoid highly processed carbs, white rice, white bread, sugar, etc, eat lean meat, fresh fruits and veggies and drink plenty of water

Diabetes: Testing your blood glucose level