Decrease of White Matter Integrity in Obese Adolescents [pdf] | Hacker News Reader

Decrease of White Matter Integrity in Obese Adolescents [pdf]

press.rsna.org

63 pointsbookofjoe32 comments

What’s the causal direction here? Do teens get obese in part because their impulse control centers malfunction? Or does being obese for years cause those parts of the brain to stop working correctly?

3rd factor?

Richard P. Bentall makes convincing argument that happiness is a psychiatric disorder.† Notably Caesar was said to prefer the company of fat men, with the implied causation that happy -> fat. One also sees this in the weight gain usually caused by SSRIs. At the same time obesity has well measured effects on many metabolic processes, so it is likely there is some effect on the brain.

† [PDF] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1376114/pdf/jme...

I was going to joke about happy stoned people, but:

Recreational marijuana use impacts white matter integrity and subcortical (but not cortical) morphometry

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4925620/

Can someone please ELI5 on the meaning of these things? Googling around just sends me down a scholarly rabbit hole of more words I don't understand.

I did that once to a paper that I don't understand. That is, I read and look up stuff until I think I understood things.

I learned a lot by doing that. But it took a lot of work, and I forgotten most of it if it wasn't added to anki. Good thing that I wrote it down in my notes.

I would imagine that in the time of Rome, fat people were likely wealthy people. Today fat people are more commonly poor.

Fatness was also more expensive then so it was a status symbol in itself when farming was the defacto "default" job to support the specialization pyramid.

That’s a super interesting essay, but I think the point is more that depression is not a psychiatric disorder.

I went from thinking it was a humorous article, to thinking it was serious after some convincing arguments, then finally concluded it was definitely a joke after reading happiness ought to be classified as "major affective disorder, pleasant type." Who can keep a straight face after reading that?

I agree with you; it is a protest.

This is extremely interesting; thanks for linking it.

> Caesar was said to prefer the company of fat men, with the implied causation that happy -> fat.

From WikiQuote [0]: "It is not the well-fed long-haired man I fear, but the pale and the hungry looking."

And from pg's determination essay [1]: "That's why Julius Caesar thought thin men so dangerous. They weren't tempted by the minor perquisites of power."

[0] https://en.wikiquote.org/wiki/Julius_Caesar [1] http://www.paulgraham.com/determination.html

do not forget that from 1980 to 2019 we went from using pure sugar to using fructose as the sugar added in food products..fructose way higher in insulin resistance etc

As far as I know, that particular theory of obesity is contradicted directly by studies conducted in metabolic wards such as https://www.cell.com/cell-metabolism/fulltext/S1550-4131(15)... and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4962163/

These studies compare short-term results of reduced fat vs reduced carbohydrate diets.

I don't see how they relate to glucose vs fructose?

That's not a global thing. In the US, they use high fructose corn syrup a lot due to artificially high sugar prices (caused by US agricultural subsidies). Here in Australia, most processed foods contain real sugar (not high fructose corn syrup) since sugar in Australia is cheap (massive export-oriented sugar cane industry and a much more laissez-faire agricultural policy).

Obesity rates in Australia are a bit better than the US, but still pretty bad – US is around 40% of adults, Australia is around 25% – sugar vs corn syrup may be a factor, but I'm sure it is a lot more complicated than just that.

I think you’ve got that backwards.

Table sugar, sucrose, is a disaccharide consisting of 1 unit of glucose and 1 unit of fructose, 50-50. “High fructose” corn syrup is high fructose relative to sucrose, but it’s generally 55% fructose and 45% glucose. Of course in HFCS they’re not bonded so do not require enzymatic decomposition. [3]

With that in mind, fructose has very low glycemic impact, and it does not trigger insulin secretion directly. Unlike glucose, it requires enzymatic decomposition (via fructokinase) in the liver. This enzyme becomes saturated and as a result the impact on blood sugar is attenuated and drawn out over time as compared to glucose. [2]

Fructose is often used as a sugar substitute for diabetics due to its lack of insulin response. It of course has its own issues, as too much can lead to NAFLD, non-alcoholic fatty liver disease — basically cirrhosis from non-alcohol causes. [1]

What is pretty clear is that sugar of any sort is bad for you.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5372893/

[2] https://en.m.wikipedia.org/wiki/Fructolysis

[3] https://en.m.wikipedia.org/wiki/High-fructose_corn_syrup

I'm pretty sure that the "high-fructose" part of the name is relative to an older process for producing corn syrup, rather than being relative to other sources of sugar. Some forms of HFCS are less than 50% fructose and are still called HFCS.

In comparison, about 70% of the sugar in an apple is fructose (most of the rest being glucose).

Apples are probably the fruit highest in fructose relative to other sugars. Most fruits (and honey and carrots) hover around 50% fructose. Cherries are probably the fruit with the lowest amount, at 30%.

One fun thing I learned is that Germans often call glucose Traubenzucker, which literally translates as cherry sugar.

It translates as 'grape sugar' though... German for cherry is Kirsche.

Traubenzucker translates to grape sugar.

I'd like to mention that if you're interested in looking at more information like this then the US Department of Agriculture has a great database for it:

https://fdc.nal.usda.gov

I recommend searching for things such as "apple, raw".

This is purely anecdotal.

I have found that obese clients have a much harder time grasping the theoretical foundation for diving than fit fit clients. I am not talking about the fitness tests, but understanding the underlying physical principles of the sport.

This has become enough of an issue that I ask about level of fitness prior to scheduling courses due to need to budget additional time for unfit clients in the classroom.

I cannot attribute this to grey matter, it is just my experience that overweight people take significantly longer to teach basic theory before even getting into the water.

Maybe that’s just because they’re not as experienced with physical activity in general?

I am talking about diving theory, not the actual activity.

If you do not use muscles regularly the nerves that control them won’t fire intelligently and you will stumble around like a buffoon. I’ve certainly never met an obese person with precise body mechanics.

I know obese people who are really great dancers. In the social dance world heavier people are typically above-average or great dancers. This isn't to say obese people are better dancers in general - just that people are prejudiced against obese dancers, and anyone who can deal with that kind of prejudice has to be really good and motivated to keep showing up.

Yes this is a survivorship bias I would say.

From my experience when I was teaching yoga classes there were different kinds of obese people. Some were super flexible and very good at moving their large body around in a world that didn't accommodate them whereas others had zero body awareness, were stiff and could barely move. There are different reasons why somebody is of a certain body type. Some skinny people are anorexic, weak and have no understanding of their body. Others are skinny because they are super fit. Superficially they look the same but are actually totally different.

I had an obese yoga teacher. She was just as good at the moves as any other yoga teacher I've had. Was pretty surprising.

It’s possible but not optimal. The same instructor in a lithe body could do so much more.

Reply on news.ycombinator.com