This is Dr. David
if his hemoglobin a1c is under control and his fasting glucose levels are normal, then his pancreas is working properly and making insulin when he needs it.
when he eats pasta and candies, his blood sugar does go up to possibly 130 or 140 or so, but his pancreas produces insulin to help bring down his blood glucose levels.
so it doesn't sound like your father has diabetes at this point.
if he walks and exercises some after he eats or plays some pingpong, this can help bring down his blood glucose levels as well.
but it is a good sign he hasn't developed diabetes at his age of 88, even with going to the senior social clubs.
that is a good social outlet for him. a little pasta will not give him diabetes if he walks and avoids being overweight
he should work towards eating a salad and fruits and vegetables at this next meal after pasta to help bring down his glucose levels
let me know if you have questions.