Mashed potatoes is a big one for me. Would never eat 5 boiled potatoes, but if I make mashed potatoes out of them I'll happily eat that much and quite possible still want more.

Orange juice has a drastically higher GI than oranges because your body more rapidly absorbs sugar from juice than from pulp. It's not just the quantity.

The process of juicing already leaves some waste out and you are probably also removing the pulp from the juice itself.

OP was talking about the differences between eating a certain food and eating that same thing after liquifying it as a whole.

>I wouldn't eat 3 oranges in a row

I would! I tend to go overboard on fruit if I don't stop myself. Apples, oranges, blueberries, cantaloupe, all so delicious...Not always pleasant for digestion and probably a bit of sugar rush, but do you know of any more serious health effects?

Eating too much sugar has serious long term health effects.

Ignoring the effect on your teeth, it was my understanding that the fibre in fruit helped counteract many of the negative effects of fructose (at least, keeping your insulin in check). I don't have any proof on hand, so perhaps I'm wrong.

There's afaik a rather big difference between freshly squeezed orange juice, and fruit juices that have been pasteurised. I'm not sure there's that big a difference between eating an orange and drinking the juice - other than the simple fact that the orange will contain "more stuff" that is "not sugar" than the juice - hence it'll be easier to increase sugar intake by drinking, say a litre of orange juice a day, and eating some food - rather than eating six(?) large oranges and being reasonably full.

Absolutely. I'm assuming eating an orange would have more fibre than a squeezed orange.

Buying "smooth" (no "bits") juice I would assume is missing most of the fibre.

Fructose is low GI, so there is a small insulin response only.

Ah, you are right. I think I'm misremembering. I'm basing most of what I wrote on https://www.youtube.com/watch?v=dBnniua6-oM but I watched it years ago and my memory isn't the greatest. (I also didn't fact check the video's content, so... grain of salt and all that, it does seem well sourced though)