Simply get Hbaic  and Fasting blood glucose done to rule out diabetes.

A person is a diabetic if he has a fasting sugar of more than equal to 126 mg% and a post prandial of more than or equal to 200mg% after 75gm oral glucose. A person is said to have prediabetes (if Fasting sugar is between 99-126mg% and post prandial sugars are 140-200mg%).....Normal sugar is fasting less than 100 and pp less than 140mg%.... HbA1c more than 6.5% is diabtes I would advice you to go to a reliable lab and test fasting and do a post prandial after 75gm of oral glucose after advice from your physician.....you could get HbA1c also done... If you still have pre diabetes, medicines maybe indicated after a trial of diet and exercise...

Hello there...I can understand your concern. If it's the postprandial glucose levels you are talking about, then as of now he can relax. For post prandial blood sugar, 180 is the upper limit. You can ask him to follow a healthy diet and get investigated regularly. kindly consult a general physician for further evaluation.