No no you see, Americans work* so much, they don’t have time to first learn and then practise to cook healthy meals at home. Hence fast food chains!!
*work American style, as in staying at work long hours but also spend about 60% of their work day chatting with co workers, or on the phone, going on personal, non-work related errands, browsing the internet, selecting, getting, eating, and ridding their bowels of food.