"Overeating drives weight gain" is like "more movement on the gas pedal causes speeding". Yes, but uninteresting. "Loud rock music makes people drive faster" is

"Overeating drives weight gain" is like "more movement on the gas pedal causes speeding". Yes, but uninteresting. "Loud rock music makes people drive faster" is not saying the same thing, and is interesting. Even if it reduces back to "they're going faster because they move the gas pedal more".