Good post mate, and great conclusion! The term 'superfood' is thrown around left right and centre for any new food which enters/comes back into the market. A few years ago it was mushrooms, then kale, and so on. But as you say, no single food can form a whole diet! A lot of it is actually just a marketing strategy to sell foods (you'd need a good marketing strategy to be able to sell something like kale...). The worst part about this whole 'superfood' thing is that it makes people miss the point that diversity in fruit and vegetables is what makes a healthy diet. More importantly, it hides the importance of eating seasonal and local food - this is the food which has the highest nutritional content and has the least externalities (even if food is produced intensively, the fact that it travels less far produces less externalities than food that's wrapped up in the global food system).
Thanks for sharing this quality post!
Edit: just saw this has no votes and views, you're getting a resteem!! Referenced work like this needs to be shared more on steemit! :)