Picky eater

Mone

My son used to eat everything. Now he doesn't want to eat meat anymore unless it's fried. He doesn't like veggies anymore. Wants sweets, fruit and carbs. Every weekend he's with my mom and she sneaks him bites of sweets and doesnt make him veggies. What can I do? She won't give him the food I pack for him because she says I can't cook. So all weekend he eats soul food.. fried foods and sweets. I made this enchilada bake yesterday and he wouldn't eat it because my mom said ew.