Earlier quoted context omitted.
How do you know that you're getting enough of all the different micronutrients? Humans can eat a deficient diet for a long time and not notice serious side effects, so I'm wondering if you have some kind of good way of figuring out whether the different micronutrient quotas are fulfilled properly.
How does anyone? I have plenty of coworkers who eat fast food for every lunch and not much better or more diverse for dinner. Certainly they are not getting all the different micronutrients?
Other than a lack of fiber and ease of consuming too many calories, one could do much worse than fast food--McDonalds, Taco Bell, etc. I think it's easier to get it wrong using a so-called whole foods diet. The ingredient diversity of fast foods makes it more fail-safe, particularly if you're disposed to repetitively eating the same kinds of foods.
I mean, obviously you can't subsist on french fries, but if the issue is laziness, lack of time, access to good groceries, or lack of money, it can make sense. It's difficult to beat a McDonald's Double Cheeseburger for dietary money-value!
Granted, the removal of trans fats has helped. And note that I'm not arguing a whole foods diet can't be better. I'm not recommending a fast food diet ;) But we sometimes underestimate the effort involved in following a good diet and discount the benefits of a good-enough diet.