The OP posed a hypothetical question, not a personal one, so none of the responses (including this one) are directed at individual persons. It seems to me that the one hour fast is already pretty minimal. We started with a fast from midnight; then we went to 3 hours, then to one hour. Pretty easy.
Someone forgets, and eats a grape within the hour. Some say that breaking the fast because of a mistake is no big deal. But if it’s a matter of forgetting, not intentional breaking of the fast, then what if one forgets and has a full breakfast before Mass? Why be legalistic if it was just a mistake? If the requirement for any kind of a fast is seen as legalistic, then why not just eliminate it entirely? Bring your own snacks to have during the Liturgy of the Word. No legalism needed.
Fast from midnight. Fast for 3 hours. Fast for one hour! How much more lenient can we get? Quite a bit, I suppose.
I was reading this article about the requirements for receiving the Eucharist. It doesn’t mention the fast, because it is more concerned with spiritual preparation. But on reflection, maybe it applies here too.
The Worthy Reception of the Eucharist Neglected at the Synod, by Fr. Regis Scanlon, O.F.M. CAP