>What about fruits and vegetables? I eat more of those than the staples
>you listed above.
If it is servings, that's not such a big deal. It's easy to eat snacks of fruit or have a salad for lunch. If it really is calories, that's a very unusual diet for the developed world. There is quite a bit of speculation about the health effects of our recent switch to a diet based on concentrated starch, but there is one effect that most people don't think about. The time and effort needed to eat meals of the concentrated calorie foods we have come to rely on vs. those much less dense foods like fruits and vegetables. There is some variation, of course. Some vegetables are pretty calorie dense, and we call them "starchy vegetables" because of that. But since potatoes were included in comptogf's original post, I figured you meant the non-starchy vegetables we call "fresh produce". And that's why I wondered if you might be on a very unusual diet. Getting enough calories takes more time on non-starchy foods. Look at how long chimpanzees spend eating each day. So you would have to be eating a larger number of smaller meals than the usual "3 squares a day" that people in our highly structured modern life tend to eat.
As I said, many people now go even further, eating almost nothing but starch -- and pure sugar. But we are now quite certain that is not a healthy diet.
Like ancient Rome, we today are once more importing every form of exotic superstition in the hope of finding the right remedy for our sickness.
-- C. G. Jung
Richard Wilhelm: In Memoriam (1930), CW 15: pg. 60