[wmil]

It's still disputed, but there's a lot of evidence the problem is fructose, not glucose. Meaning that bread and potatoes aren't particularly bad on their own.

Here's "Sugar: The Bitter Truth" that lays out the theory. https://www.youtube.com/watch?v=dBnniua6-oM

[whyme]

I'm pretty sure, in that video, the argument was that while glucose is still really bad for you, fructose[1] is much, much worse - it's a poison that's causing an epidemic.

1. And specifically the manufactured fructose isolates vs. natural fructose found in fruit.

Edit: rather glucose in high quantities as noted in response below.

[hristov]

I don't think so. The video says that there is nothing wrong with glucose, it is the fuel of life. Fructose is the problem. More specifically, refined fructose.

This by the way reflects real life. You can find populations that live on mostly bread and pasta, or mostly rice and noodles and they do not have obesity problems. It is only when refined sugar enters the diet that obesity shows up.

[_delirium]

> And specifically the manufactured fructose isolates vs. natural fructose found in fruit.

Is there an explanation as to why this would be the case (if it is)? With a lot of vitamins the argument is over absorbability of different forms, e.g. there are various forms of dietary calcium, and various kinds of calcium supplements, and they may not be equivalent. But my understanding was that fructose in fruit is pretty much just fructose, readily absorbable just like the isolated version is. The only plausible difference I can come up is concentration; there's a limit on how much fructose you can get from fruits because the average person is not going to scarf down a half-dozen pears in a sitting. But if high concentrations are the issue, it would also apply to concentrated "natural" fructose, e.g. the pear-juice concentrate that some "naturally sweetened" products use.

[hristov]

There is an explanation. I urge you to watch the entire video. The problem with fructose is that the liver has only a limited ability to properly process it. This if you get too much the liver processes a lot of it through the wrong pathways, and that causes all types of chaos.

There are a couple of differences with natural fructose. First natural fructose almost always comes with fiber. The fiber if processed at the same time as the fructose allows the liver to properly process more fructose. This is because the fiber provides certain nutrients which allow the liver to process more fructose along the proper pathways.

Second, natural fructose is usually in plant cells. In order for us to process these, we much first break down the plant cells in our stomach. This takes some time, so the effect is that the natural fructose does not hit the liver in the same speed and concentration as refined fructose.

This all has scientific support by the way. Lustig mentioned a study in old Caribbean sugar plantations. There they tracked the health of the masters and workers. It turned out that while both the masters and workers ate mostly sugar, the masters had a lot of health problems associated with obesity and diabetes, while the workers did not. The difference was that the masters ate refined sugar, while the workers mostly just ate raw sugar cane.

There was another study in japan, where scientists tried to give people massive amounts of sugar in the form of apples. These people did not have any of the problems associated with high sugar intake.

[raverbashing]

I think you're almost there

Fructose is fructose, there's no "natural fructose" however it's one thing to eat it pure, another one in a fruit

"The problem with fructose is that the liver has only a limited ability to properly process it."

Correct, glucose can replenish muscle glycogen, fructose can't (the liver produces both types of glycogen) - http://www.ncbi.nlm.nih.gov/pubmed/3592616

"This is because the fiber provides certain nutrients"

Fibers, per definition are not digestible but are other things that may happen http://en.wikipedia.org/wiki/Dietary_Fiber

And of course glycemic index may be a problem with sugars as well.

[_delirium]

Fructose is fructose, there's no "natural fructose" however it's one thing to eat it pure, another one in a fruit

That I can buy. What I'm more skeptical of is that there's a distinction between "manufactured" and "natural" fructose once both have been concentrated and are used as additives to sweeten other products. Eating a pear is one thing, but I'm less sure that a "naturally sweetened" product which has been sweetened with concentrated pear juice or a similar fruit-based sugar extract is really more healthy than the same product that has been sweetened with more conventional "manufactured" sugars. I don't doubt that eating an actual fruit is almost certainly better than either one.

[sizzle]

I've come to learn that "natural" is a marketing weasel word that adds nothing of value to describing a product.

[stefantalpalaru]

There's only one type of glycogen that's stored in different places. The article you linked only refers to "rapid glycogen restoration". Don't assume from that that the liver can't produce glycogen from fructose.

[a8da6b0c91d]

There is absolutely no explanation. It's just neo-puritanical mystical thinking. The only problem with eating refined sugars is the paucity of vitamins and minerals. Fruit juice is loaded with both of these, yet the lustigites still try to claim fruit sugars without the fiber are bad for you, with no sound basis.

[a8da6b0c91d]

> glucose is still really bad for you

Every cell in your body runs on glucose. To say glucose is "bad for you" is simply idiotic.

[whyme]

yeah, i should have said in high quantities, but I was just paraphrasing the video. The point was, in the video, he did not say it was just fructose, glucose can also be a problem.

[a8da6b0c91d]

It can be a problem if you're type I diabetic or are obese, both of which result in impaired insulin sensitivity.

Otherwise, you can quite healthily gorge on starch and sugars and your tissues will happily mop up the glucose and fructose into glycogen. And then if necessary into fat, but lipogensis from sugars is surprisingly inefficient and glycogen capacity is more than you probably think.

[a8da6b0c91d]

Lustig is a crackpot.

http://www.andrewkimblog.com/2013/02/quick-commentary-on-dr-...

[greenyoda]

Unfortunately, I don't have enough time or knowledge to track down and understand all the references in this article. So I need another way of establishing the author's credibility.

What are Andrew Kim's qualifications (his web site doesn't list any)? Why should I believe him more than Lustig, who is an endocrinologist who has treated and studied a lot of obese patients?