It is less important for diet controlled diabetics and type 2 diabetics who do not take insulin or sulfonurea oral meds to eat on time. This is because sulfonurea drugs actively cause the pancreas to make more insulin which lowers the blood sugar and must be counterbalanced by eating, which raises the blood sugar. If a diabetic takes an insulin injection that is supposed to lower the sugar after a meal, and they don’t eat the meal, then their sugar goes too low.

This is especially a problem with the longer acting insulins. If an insulin lasts 12 or 24 hours and the person taking it does not stay on schedule, then there could be problems.

One advantage of a diabetic who has an insulin pump is that they have no long acting insulin in their body, and the insulin they do have acts so quickly that they can actually take it AFTER they eat if they had to. That way they know exactly how much insulin to take and it works so quickly they can be much more flexible with their schedule.

To answer your question…I am not a vet, but I imagine an hour late would not bother the cat any more than it would bother any other cat.