Just a note that for diabetics, food is medicine if blood sugar gets too low.
Threads like this just flabbergast me. In my cultural background, we tend to observe the spirit rather than the letter of the law.
That said, there is no rule that one must receive the Eucharist at every Mass one attends. So if someone is bothered by that one grape, simply skip receiving until the next Mass.
Some point out that the fast seems lenient compared to past practice. Past practice wasn’t just overly strict, it was actually dangerous for one’s health. When I was a child I remember a young woman passing out at Mass because of the overnight fast, at a late-morning Mass on a very hot and humid summer day; my father, good samaritan that he was, bundled her into our car and we drove her home. We’re not all Carthusian monks…
Fortunately it is a matter of discipline, not doctrine and the Church could and did change it.