Hear me out. There's nothing innate to an object that makes it "food". It's an attribute we give to certain things that meet certain qualities, i.e. being digestible, nutritious, perhaps tasty or satisfying in some way, etc. We could really ingest just about anything, but we call the stuff that's edible "food". Does that make it a social construct?
No, it’s not a social construct, it’s a description of things that are consumed for nutritional value. Sure, “food” is a social construct in that it’s an English Language word used to describe said items, but every single life form consumes some form of food, regardless of said life form’s society (or more often lack thereof).
Also there are literally objective things innate to certain objects that make them food so you’re entire initial premise is idiotic.