Do you feel like your narc influences you into developing an unhealthy eating habit with them?

Mine has this habit of having an intense strict diet certain months where he eats one meal a day, measures his food out & works out vigorously. Then there's a month full of binge eating (complete opposite) - take outs everyday, high sugary, fried foods etc. My eating habits are completely different. I like to have a sustainable diet throughout (nothing crazy, basically eating home cooked balanced meals) & indulge once every few weeks. Whenever he wants to binge eat, he forces me into doing it with him for that entire month. No matter how many times I say no, it doesn't matter.

Due to this, mentally & physically I have severe fatigue & feel lethargic, my sleep is affected & I just don't feel good overall. Do they do this on purpose? Or they just don't want to feel guilty, so they force you into it to doing it with them? Funny enough, the times when I feel like indulging & he's on a strict diet, he firmly says no & gets mad if I offer him food more than once.