My most faithful reader, Katherine, asked me to investigate the most nutritious fruits and vegetables, recalling that she'd read an article on the subject years ago.
A simple Google search turns up multiple articles on the subject, but while sources agree, generally, that the most popular fruits and vegetables in the American diet (iceberg lettuce, potatoes, apples, bananas) aren't the most nutritionally dense, they don't agree on which specific fruits and vegetables are the very best.
That stands to reason, given that no fruit or vegetable is an island: they all provide part of the vitamins, nutrients, and fiber we require every day - and everyone has different standards as to what aspect of "nutritious" is most important. Most sources agreed that an easy way to get balanced nutrition from fruits and vegetables is to eat a variety of different colors, since color generally indicates what nutrient a certain fruit or vegetable contains.
However, most sources agree on the following:
dark green leafy vegetables (spinach, collards, kale, chard, mustard greens, etc.)
berries (all kinds)
While lots of lists include at least one tropical fruit, they're evenly split between papaya, guava, and mango. Since these lovelies have similar taste profiles, perhaps they are similar nutritionally. Similarly, several sources credit asparagus and artichokes as being "nutritional powerhouses," but there wasn't enough consensus for me to include them. And perhaps the biggest surprise for me is that avocadoes, while they made a few lists, weren't universally listed - I bet they're a victim of bias because they're so fatty and nobody wants to believe healthy vegetables can taste like butter and still be good for you.
Bananas and apples get harsh treatment here, since they're so common and not as nutritionally rich as the selections from this list - but apples are great for their fiber, and my muscles get all twitchy when I don't have my potassium-rich banana smoothie in the morning. So to avoid being overly diplomatic, I've got to say that I think a "most nutritious" list is unnecessary for folks who eat a variety of fruits and vegetables every day, which is exactly what nutrition experts recommend. Though it would be easier if we could eat the same one or two plant foods every day and get the maximum possible nutrition, that's just not possible, and this type of list could lead folks to limit themselves.
Except spinach. I'm pretty sure spinach is the greatest food known to humanity.