A woman, apparently with some affiliation to WHO, lectured today about how much sugar food has these days. Nothing I didn't know before, until a weird point came up. Apparently, if I eat an apple raw, the sugars in it are completely harmless to me, but if I squeeze it into juice, they're just short of Hitler. And the same if I slice and sundry it. I questioned this, and she handwaved something about removing the natural fibers in the fruit, but how does that have anything to do with the sugars? Why would refining my food in a way that doesn't change its chemical composition somehow change its sugars for the worse? Can anyone explain this to me?
I think (And that's important there) that it's kind of like... Okay, shit, this is gonna be hard to explain with my limited knowledge.
Anyway, apparently, if you take a sudden rush of sugars, your body, in order to keep homeostasis, releases tons of insulin to pack that sugar away, problem is, said insulin doesn't really know when to stop, so your body will send out signals to make you eat more sugar because now your body is running low and you need that shit right now, it creates a cycle pretty quickly, but if you eat something like an apple, your sugar intake is buffered, so your body won't freak out, like slowly increasing the temperature in a bath, I guess.
However, if you juice enough apples to make a glass of apple juice, what you've got there all the sugar concentrated into a small package, without anything to buffer it, so the cycle starts.
That doesn't really explain everything. By that logic, if you need to juice several apples to make a glass of juice, then
it's still equivalent to the amount of apples it took. So, a single apple's worth of juice would approximately have as much sugar as a single apple, discarding the sugars in the parts you don't get in the juice (so even less of 'em).
Likewise, with sundried apples, and this doesn't even have the excuse of fiber, because sundrying has fuck-all to do with removing the fiber in any way. It removes *water*. That's why there's 'drying' in the name of the process.
And even still, fiber doesn't explain anything here. At best, you could say it makes you less hungry, since it's pretty much literally (untreated) paper - it's not digested, essentially the perfect inverse of 'empty calories' - it takes some place in the stomach making you feel fuller, but is nutritionally useless.
E: However, an important distinction is whether we're talking about freshly squeezed juice or commercially available juice. The latter are sometimes sweetened.
Incidentally, this is the right thread and subdiscussion to bring up a weird thing I noticed: it seems like I work better starving. I went through this Monday on a handful of muesli, a 30 gram granola bar and a morning coffee, so ~300 kcals total, until the late evening and I've noticed being more alert and clear-headed, better reaction times, and hell, even had better posture. Not the first time either, I've been noticing that throughout this summer. I wonder, is that some kinda evolutionary hack to make you go into 'hunting mode' to FIND ME SOME GODDAMN FOOD NOW, LOOK, SEE IT NOW?