Not true. Crap fuel will give you crap MPG, and could clog up fuel injectors. It won’t necessarily ruin your engine.
What ruins car engines is running on low coolant, making it run hotter and that burns up valves. Another thing which will ruin the car engine is using low quality oil and keeping it too long in the engine and letting the level drop below recommended.
Good points, perhaps the better analogy is using crap fuel sure ain’t going to let you run at your optimum, and garbage food is like garbage oil.
If someone believes in evolution, or divine creation, there’s just no point in fueling either a magnificent machine or God’s creation with crap.
It’s not really that hard, or expensive to eat healthily, but it does take more thought than just shoveling stuff into our bodies that’s been carefully engineered to suit our taste buds but not carry good nutrition-for-caloric content.