I posted this is in the exercise forum, but it’s also true that avoidance leads to problems with food. You can become lactose intolerant by avoiding dairy products, but in many cases you can also regain your tolerance by eating dairy and enduring a couple of weeks of gas. You become insulin resistant when you avoid carbs. And I hear that many vegetarians get a stomach ache if they try to eat meat, because they’ve lost the ability to digest it.
One more example, while I’m indulging my tangents: Astronauts lose muscle and become weak because it’s too easy to move around in space. It seems our bodies need to be constantly challenged in order to thrive.