Today I learned

Yeah and I don't think OP's labelling this as a "myth" is really clarifying anything. It's not "true" or "false": it's an overly vague and broad generalization from one study. It's like if someone told you "You eat half of your fat at breakfast". Is that true or false? Well, it depends a lot on which "you" you're talking about and which day you're talking about, but in any case it doesn't make much sense to generalize it into some sort of bizarre universal truth or falsehood.