Here's what helped me not get stuck.
In traffic and on busy days:
I always carry a "safe snack" — something simple and fresh that I know I tolerate (fruit I can handle, plain crackers, a bottle of water). Hunger makes me make bad decisions; if I have something safe on me, I don't end up desperate at the first fast-food place.
On holiday:
if I can, I pick a place to stay with a little kitchen. One simply cooked meal a day keeps my bucket under control, even if I eat out the rest of the time. And I do my "homework" beforehand — I look up a few spots with fresh food near where I'm staying.
When I'm flying:
I don't rely on the plane food. I bring something of my own.
The golden rule everywhere:
on unpredictable days, I keep it simple. Fewer ingredients, fresher ones. It's not the time for exotic culinary experiments — it's the time for what I know works.
And, maybe most important of all: I let it not be perfect. One harder day on holiday doesn't ruin the whole holiday. I go back to simple, drink water, and have patience. A life on the move is possible with HIT — it just takes a little preparation and a lot of kindness toward yourself.
What I always keep in my bag
I keep a little permanent "kit": a bottle of water, a safe snack (the fruit I tolerate, some plain crackers) and, if I'm away longer, a few prepped portions. It takes up no space, but it saves me from the moments when hunger plus no options pushes me toward choices I regret. Five minutes of prep at home saves me hours of discomfort.