|from this study, image from this post|
For any newer readers, TWICHOO stands for Taubes Wrong Insulin-Carbohydrate Hypothesis Of Obesity. Version 1.0 was that which was put forth in Good Calories Bad Calories. In this version, Taubes put forth four ways by which the carbohydrate could promote obesity:
1. Carbohydrates stimulate insulin which stimulates fat storage and/or traps fats in our fat cells so fat accumulates.
This was pretty much the "lead singer" of his Barbershop Quartet singing the TWICHOO jingle. Carbs stimulating insulin basically led to chronically elevated insulin levels. The other three are:
2. Excess carbohydrates are converted to fats by de novo lipogenesis, and these fats accumulate in our fat cells.
Tenor hitting the high notes? Then
3. Carbohydrates stimulated insulin spikes lead to chronically elevated insulin (hyperinsulinemia) that leads to the development of insulin resistance. This IR begins in the muscles (accelerating process 2 and enhancing process 1 for more fat accumulation) until the adipocytes eventually become IR themselves.
The harmonizing baritone it is! And who can forget the fourth singer, the bass in my mind,
4. Carbohydrates provide the backbone molecule, alpha glycerol phosphate (aka G3P), for the process by which fats are "fixed" or "trapped" in the fat cells. Dietary carb is required for G3P and the more carb, the more G3P, the more fat is "fixed" and accumulates.
If one listens to Taubes' lectures over the years, it becomes obvious that the tenor left the group first. Not around the nutrition blogosphere, mind you, but from Taubes' lectures. You'll hear the voice go down as he says it wasn't as much as he initially was led to believe (from his cherry picking). Folks like Eades, Sisson and most especially Gedgaudas never got the memo on the departure of Denny L. Gee from the group. Rumors started circulating in 2009 that the bass, Al Phageepee was disenchanted with his role in the group. But Taubes fought mightily cutting deal after deal with Al to keep him hanging on until summer of 2010 rolled around. Rumor has it Al left for a weekly gig singing solo in The Asylum Bar & Lounge.
This left the duo of G. Diddy Lucose and the singer who insisted on being called "The Resistance". It got contentious who was singing melody and who was singing harmony. For a year or more, Taubes tried different roles for his remaining duet. He tried to replace Denny and Al too, to no avail. Finally, sometime earlier this year, Gary appeared to have decided on his final form for his Butchershop Quartet. It would be "The Resistance" singing a different tune in the lead, with G.Diddy harmonizing, and the replacements Taubes finally found for Denny and Al. Rumor has it that G.Diddy is not so happy in the supporting role, but he's got a book to sell and some undisclosed stock options in UCAN have also been rumored to be part of the deal. The new TWICHOO X.0 goes something like this:
1. Carbs still spike insulin, and insulin still traps fat in fat cells, and scientists are all still idiots operating at sub-optimal intelligence and all that. Such is a given, but now:
2. The antics of carbs and insulin from #1 are likely not the cause of obesity after all so long as the body remains sensitive to that insulin. The Japanese eat white rice after all.
3. Fructose, conveniently another carbohydrate, causes insulin resistance in the liver. This insulin resistance now leads to hyperinsulinemia and exacerbates both glucose and insulin spikes from consuming glucose.
4. Hyperinsulinemia causes fat to not only accumulate in the fat cells, but this locking away of this fuel source causes the rest of the body to suffer a state of "internal starvation" leading to out of control appetite and consumption of excess calories.
Singing tenor we now have Hy Perinsulin and on bass, in a nod to the Hall & Chow foundation of reality, a lucrative but much hushed contract was entered into with Cal O. Riezcount.
But Houston, we have a problem with the Butchershop Quartet. It hangs together even less cohesively than did the original group. And LIRKO, more of a minor pestilence to TWICHOO 1.0, proves to carry the bulogic plague that should go down in the history books for bringing about the extinction of the Gen X TWICHOOB. Why do I say that? Well because v. X.0 hinges entirely on hepatic insulin resistance. While one could weave scenarios for the cognitive dissonance that LIRKO posed to v. 1.0, there's no getting around this specific in the reincarnation.
If TWICHOO X.0 is correct, then LIRKO should be a porker. LIRKO is a mouse genetically given (poor things) the ultimate hepatic insulin resistance -- it has no insulin receptors in its liver. What happens is that insulin fails to do the major thing it is tasked with in the liver -- suppress gluconeogenesis. This mouse is genetically engineered to be the model what TWICHOO X.0 claims is diet induced. Yet it doesn't fatten. And it's not because of some cross-signaling preventing adipocytes from taking up glucose or retaining fatty acids. Indeed NEFA are suppressed by around 40%, and yet this mouse doesn't resort to overeating to get compensate for its "internal starvation".
I'll leave you with a quote from GCBC:
But the greatest single change in the American diet was in fact the spectacular increase in sugar consumption from the mid-nineteenth century onward, from less than 15 pounds a person yearly in the 1830s to 100 pounds by the 1920s and 150 pounds (including high-fructose corn syrup) by the end of the century. In effect, Americans replaced a good portion of the whole grains they ate in the nineteenth century with refined carbohydrates.
And here I thought they replaced lard with sugar ... but I digress.....
My question is this. Where's the missing obesity epidemic that began in the mid-19th century? The grand PhD thesis does not support TWICHOO 1.0, X.0 or any of the nuanced versions in between. A good scientist ditches hypotheses when evidence fails to support them. Well, a good scientist formulates hypotheses based on observations ....