This was very well written.
I grew up with a mother, obsessed with overeating.
Without knowing more than what you wrote, I am left asking what is wrong with a teenage boy wanting chips at night? I am thin, and you bet I eat junk at night. I worry you are putting off your own issues onto "Rory"?
The less I treat food as a big deal to my kids, the less they care. The more I act like it is a forbidden fruit, the more they want it.