English Translation
Please help yourself to any food you like.
I think the de shouldn’t be there: “Toma cualquier cosa que te apetezca comer.”
Update: or maybe it’s OK, if you consider “toma cualquier cosa de comer que te apetezca”. 
Please help yourself to any food you like.
I think the de shouldn’t be there: “Toma cualquier cosa que te apetezca comer.”
Update: or maybe it’s OK, if you consider “toma cualquier cosa de comer que te apetezca”.