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Welcome all seeking refuge from low carb dogma!

“To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact”
~ Charles Darwin (it's evolutionary baybeee!)

Friday, September 9, 2011

Metabolic Mad Libs

Anyone here remember Mad Libs?   These were game books of sentences, short stories even, where you would be asked to fill in the blank with a certain type of word (adjective, noun, profession, color, etc.) and the result would often be a very funny sentence/tale.

Let's take the carbs → insulin → obesity hypothesis and turn it into a Mad Lib.  Although my intent here is not one at humor, but instead to demonstrate how LC logic fails us.  

Here's a starting paragraph one might find in support of TWICHOO.

Insulin drives esterification and the storage of triglycerides in fat cells.  Dietary carbohydrates stimulate insulin therefore stimulate fat storage.  Obesity is associated with high fasting levels of insulin, therefore hyperinsulinemia causes fat accumulation.  Dietary fats don't stimulate insulin therefore fats have no influence on fat accumulation.  A deficiency in insulin [Type 1 diabetes] leads to weight loss.  Therefore, carbohydrates drive insulin drives fat accumulation.  Carbohydrates make you fat.


"Mad Libified" this becomes 

__________ (hormone) drives esterification and the storage of triglycerides in fat cells.  Dietary __________  (macronutrient) stimulate __________ (same hormone) therefore stimulate fat storage.  Obesity is associated with high fasting levels of __________  (same hormone), therefore hyper__________ (same hormone)emia causes fat accumulation.   Dietary __________ (different macronutrient) don't stimulate __________ (same hormone) therefore __________ (same macronutrient in sentence) have no influence on fat accumulation.    A deficiency in ______________ (same hormone) leads to weight loss.  Therefore, ______________ (first macronutrient) drive __________ (same hormone) drives fat accumulation. ______________ (first macronutrient) make you fat.

Now, this is not how the game is played normally, but let's fill this in deliberately here with 
facts that are known about another hormone involved in fat cell metabolism, ASP:

_ASP_ (hormone) drives esterification and the storage of triglycerides in fat cells.  Dietary _fats (macronutrient) stimulate _ASP_ (same hormone) therefore stimulate fat storage.  Obesity is associated with high fasting levels of _ASP (same hormone), therefore hyperASP(same hormone)emia causes fat accumulation.   Dietary _carbohydrates_ (different macronutrient) don't stimulate _ASP_ (same hormone) therefore _carbohydrates_ (same macronutrient in sentence) have no influence on fat accumulation.  A deficiency in _ASP_ (same hormone) leads to weight loss.  Therefore, _fats_ (first macronutrient) drive _ASP_ (same hormone) drives fat accumulation._Fats_ (first macronutrient) make you fat.

Let's take out the "Mad Libbing" and we have:

ASP drives esterification, the storage of triglycerides in fat cells. Dietary fats stimulate ASP therefore stimulate fat storage.  Obesity is associated with high fasting levels of ASP, therefore hyperASPemia causes fat accumulation. Dietary carbohydrates don't stimulate ASP therefore carbohydrates have no influence on fat accumulation.  A deficiency in ASP leads to weight loss.  Therefore, fats drive ASP drives fat accumulation.  Fats make you fat.

All of the above paragraph is true.  Except, of course, that fats (per se) make you fat.
Unless there's anything to LC logic I suppose.  {grin}



5 comments:

Duffy Pratt said...

It looks to me like the whole problem stems from this sentence "Dietary fats don't stimulate insulin therefore fats have no influence on fat accumulation." This sentence has already presumed that insulin is the only proximate cause of the accumulation of fat. The chain of reasoning didn't establish that.

To me, the irony of this kind of thinking is it is very similar to the sort of thinking that Taubes debunked having to do with cholesterol and dietary fat.

Evelyn aka CarbSane said...

Just so we're on the same page Duffy, are you saying that this is not what Taubes is saying?

"Dietary fats don't stimulate insulin therefore fats have no influence on fat accumulation."

Duffy Pratt said...

I'm not saying that at all. In GCBC, he argued that insulin was "primarily responsible" for fat accumulation. It seems that he has since gone on to assume that insulin is completely responsible for it. So the mistake in the logic all stems from the "therefore" in the sentence: "Dietary fats don't stimulate insulin therefore fats have no influence on fat accumulation." As a logical matter, that would only be true if elevated insulin was a necessary cause of fat accumulation in all cases. And, as far as I can see, no-one has demonstrated that. Indeed, if what you are saying about ASP is true, then its pretty obvious that there is more than one mechanism for the accumulation of fat.

Evelyn aka CarbSane said...

Thanks for clarifying Duffy. So would it be fair to say you disagree with Taubes' theories?

Duffy Pratt said...

Yes, it's fair to say that I don't accept Taubes' idea that elevated insulin levels caused by excess consumption of carbohydrate is the root cause of all the diseases of civilization. I came to the web about this subject because I was skeptical of these claims. (I was skeptical about similar claims when I first read them in Protein Power about 12 years ago, though they were more plausible than Eades theory that low carb dieting worked because we pissed away so many unused ketones.) Having read stuff on the web, and mostly here, I'm pretty well convinced that this part of the book is just wrong.

As I said before, I was more impressed with his laying out of the bad science behind the demonization of dietary fat. I also liked his rejection of CICO as a "cause" of obesity, and still do in many ways. But I'm more persuaded now that the word "cause" is even slipperier than I thought. If talking to an individual who asked for advice on losing weight, I would tell the person to eat less and to do some exercise. (My favorite exercise actually doesn't involve much movement. Instead, we hold really hard postures for an extended period. Stillness can be even harder than moverment.) And if the person were diligent, I would expect the weight loss to come pretty easily. Having said that, CICO doesn't do anything to "explain" the obesity epidemic. When asking why the population as a whole has become fatter, it doesn't add much to say that, on average, the population has been in positive caloric balance.

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