We don't have the particular issue at our parish.  But I am always starving during Mass (earliest is 9am), and I don't know what to do about it.  I wish I had control over my stomach!

Honestly, I would just go to a different mass. Priests before the council were trained to give sermons of no more than about 7-8 minutes. If a sermon goes on for an hour, the priest is diverting attention away from the mass and turning the sermon into a lecture. It happens, I've been there. They really should save the extended talks for after mass or an adult catechism class.

Otherwise, I'd get up, eat before the three hour fast, and drink something sugary before the 1 hour mark, or maybe drink water right before mass to fill up.