Hmmm...I'm not a food scientist or doctor, but the logic here raises questions about many health axioms:

1) If the sugar and carbs in bananas are "bad", then you might as well say the same about most fruits. I thought the fiber in fruits (and micronutrients) justified those sugary carbs.

2) I get that you're saying berries and citrus are "better fruits" (that's mostly the fruit I eat), but if you are knocking the banana smoothie, why not the apple smoothie also? And some vegetable smoothies? (Ick)

3) Re: vegetables, there is also the "good and bad" vegetable argument (high glycemic carrots, potatoes, corn, beets, vs low glycemic lettuce, broccoli, cauliflower, cabbage, peppers), but this also ignores some of the micronutrient value of at least beets and carrots?

4) Shouldn't all this be viewed in the context of one's activity level? I mean a highly active person may need more of those sugary carbs?

5) I'm not taking any chances, from now on my smoothies will be made of watercress and ice.