The normal levels for blood sugar for diabetic patient is fasting less than 126 mg/dl, and random less than 200 mg/dl.
He should avoid drinking as much as he can thats why it is toxic to the liver
Avoid sweets and take regular good exercise to control the blood sugar levels.
Have eye examination yearly for Diabetic changes in the eye called as Diabetic Retinopathy
Have Renal Function Tests yearly to see the toxic effects of Diabetes
on the kidneys.
He can use all kind of fruits and vegetables just avoid sweets.
I hope I am sucessful in solving your query If you have further you can ask me.
Dr. Azhar Sattar