[zamfi]

I think th e poster you are responding to is making the point that long-chain refined carbs, which is what you get in e.g. pasta, breakfast cereal, oatmeal, rice, etc. (even if “whole grain”, most of which just adds back fiber but has already irreversible separated that fiber from the carbs) are perceived by many people as part of a balanced diet, etc — but they are basically sugar, because they are metabolized into glucose very quickly.

[tejohnso]

> basically sugar

I think we should be careful here about calling glucose "sugar" and talking about harmful metabolic process because most people think sucrose when talking about sugar. And the potential harm from sucrose, glucose+fructose is quite different than glucose alone. Eating 100g of pasta, what you call "basically sugar", is not at all the same as eating 100g of table sugar. There's just so much room for misinterpretation and miscommunication around food. And in addition, so much is unknown.

[zamfi]

You are correct, I was imprecise. 100g of pasta is close to 100g of glucose, while 100g of table sugar (sucrose) is ~50/50 glucose and fructose, the latter of which has a completely separate metabolism.

But both cause a huge glucose spike (ignoring fructose metabolism for now) and in that respect they are quite similar, and very different from basically any other kind of food in terms of metabolic response.

[canucker2016]

carb != sugar

sugar is glucose + fructose.

The human digestive system metabolizes fructose differently than glucose.

Bears eat lots of fructose prior to hibernation, birds eat lots of fructose prior to migrating south for the winter.

Consuming lots of fructose, say in a large container of carbonated drink dosed with high-fructose corn syrup/sugar, sends signals to your body to stop burning fat and start storing fat.

Ever hear someone say, "I just have to look at food and I gain weight". Well, those people have probably consumed enough fructose such that their body started storing food calories as fat.

see "Peter Attia - #87—Rick Johnson, MD: Fructose—the common link in hypertension, insulin resistance, T2D, & obesity?"

at https://www.youtube.com/watch?v=LbSic4Oo8ME

[quietbritishjim]

> sugar is glucose + fructose.

That's not the definition of sugar. Not even if you meant sucrose there (which is different from just a mix of glucose and fructose). Wikipedia puts it:

> Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. ... White sugar is a refined form of sucrose.

I know Wikipedia is not perfect but that matches what I've seen in the past. For example, fructose (by itself) is absolutely a sugar and it would be outrageous to claim it's not because it's not sucrose.

[infinite8s]

You are correct that that is not the scientific definition of sugar, which is generally any 5 or 6 carbon ring molecule.

However when most people talk about sugar they are referring to table sugar, which is a molecule of glucose (a six carbon ring sugar) chemically bonded to a molecule of fructose (a 5-carbon ring sugar) - otherwise known as sucrose. The first thing your body does when it sees sucrose is split them into a molecule of glucose and a molecule of fructose (this happens in your small intestine). Glucose can be metabolized right away, in any cell, however fructose needs a bit more processing in the liver before cells can use it to generate ATP.

[quietbritishjim]

> ... when most people talk about sugar they are referring to table sugar ...

What can I say? (shrug) I disagree, that's not my experience from talking to people in person (about diet; obviously it's a different matter if you're talking about cake ingredients). Anecdotal evidence from replies here on HN seems to agree with you though. Who knows what's more common in reality.

[quietbritishjim]

Hmm, perhaps you're right. I suspect that "highly refined" is an ambiguous term. A quick Google suggests it mostly refers to sugars but also refers to things like rice cakes and white bread that are mostly starchy; maybe it depends, in part, what things it is packaged alongside rather than just the chemical composition of the carbs themselves e.g. whether it is included alongside a fair amount of fibre.