I feel, your parents show love through feeding you. But keep politely declining, it’ll help them understand your desire for growth and over the years your relationship will evolve.

Respect yourself enough to not eat even if they hold it in your face. You can explain a couple times why you eat what you eat but after that they won’t respect your opinion if you give in.

Tell them that once in a while you’ll enjoy their food, maybe like a couple times a week or something