This is a fun question! There isn't really a specific reason why healthy food is called "food." It's just a general term for anything we eat. Here's why:

* "Food" is a very broad term: It encompasses everything we consume for nourishment, whether it's a perfectly ripe apple or a bag of chips.

* Healthy and unhealthy are subjective: What one person considers healthy food, another might not. There's no single definition of "healthy food."

* Language evolves: The word "food" existed long before the modern concept of "healthy eating" was established.

It's like saying why is a car called a car: It's just the name we use for a particular type of vehicle.

So, while we often talk about "healthy food" and "unhealthy food," the term "food" itself doesn't have a built-in value judgment.