This happens to me too. Eventually, hunger does win and I’m forced to drop what I’m doing and get a bite to eat. And wouldn’t you know it, I feel better after eating.
One suggestion I could offer that I do all the time is to pack snacks (i.e. apple, banana, protein bar, yogurt, nuts) and water. Eating something every couple of hours – or so – helps me keep going without depleting my body of energy.
Recently, I experimented with leaving my bag of snacks somewhere else other than my desk. For example, the break room. The purpose was to push me to stand up, stretch my legs, circulate the blood, take a short break, disrupt my hyperfocus and get something to eat.
I found this exercise to be helpful in resetting priorities.