If we consider at this point for this age the weight is low, but we should also consider the interval weight gain. So it is helpful if we can now how much weight he has gained over last 3-6months. And as per the blood sugar levels , if there is no symptoms of low sugar like drowsiness, excessive sweating, lethargy etc then we can take this as a normal level. But still needs a monitoring with proper post Prameela sugar level.

Yes sugar levels are normal, if u have concern go for fasting sugar, and hba1c or does he have any dizziness, weight loss, increased water and food intake as weight is little bit lower side, but 98 is normal after 4 hrs of meal