Stephan Guyenet, neurobiologist who studied the Neurobiology of the regulation of body fat, wrote a critic long, detailed Gary Taubes book, Good Calories, Bad Calories on his wonderful blog, Any Source of health.
A few weeks on Gweek, I examined follow-up to Taubes book, Why get us Fat: And What to Do About It, which is a slimmed down version easier to fill of good Calories, Bad Calories. I hope meets Taubes this interesting criticism. But it was not posted on his blog since April.
What I want to discuss, it is a hypothesis. This is the idea, advocated by Gary Taubes, carbohydrates (especially refined carbohydrates) causes obesity by elevation of insulin, causing increased fat storage in fat cells. To demonstrate that I represent this hypothesis with accuracy, here is an excerpt from his book Calories, bad Calories:
This alternative hypothesis of obesity is three separate proposals. First, as I have said, is the basic proposal that obesity is caused by a lack of regulation in metabolism of fat, and thus a defect in the distribution of energy, rather than an imbalance of energy intake and expenditure. The second is that insulin plays a key role in this process of fattening and compensatory behaviors of hunger and lethargy. The third is that carbohydrates and particularly refined carbohydrates - and perhaps the fructose and content, and hence the amount of sugar consumed - probably are the prime suspects in the chronic elevation of insulin; Therefore, they are the ultimate cause of common obesity.
There are three parts to this idea. I will deal with each of them separately. I know that many people expect (in the hope of?) a bitter withdrawal of Gary Taubes, but this is not what will happen. I am not bitter, but I do not think that some scientific wrongs must be straightened for the ancestral health community as a whole. I also agree that there is a lot of useful information in the books of Taubes.
Part i: a defect in metabolism of fat?
The first part of this hypothesis says that the energy balance is not the ultimate cause of material gain fat, it is the proximal cause. Taubes is not in disagreement with the first law of thermodynamics: he understands that fat accumulation depends on how much energy is entered into the body leaving vs. However, it considers that all of the industrialized world is a not only wake one morning and decide to eat more calories, so something must be driving increased calories consumption.
He cited the research of Dr. Jules Hirsch and Rudy Leibel, various underfeeding and overfeeding of studies, studies of lipectomy and evidence of rodents genetically obese, to demonstrate that body fatness is biologically regulated rather than the passive result of consumer behaviour and voluntary food exercise. Then, he advanced the idea that this is a change in fatty regulatory system of the body behind obesity. This may seem familiar because I have written about this several times on this blog. So far so good.
This is where he should have mentioned leptin signaling, which would have taken the book [in] scientifically exact direction. Leptin is the system that the Dr. Jules Hirsch and Rudy Leibel showed in carefully controlled human studies is responsible for the metabolic defect it is (1). It is also the system which is mutated in rodents genetically obese, he discusses (2, 3). It is still no mention in the book. It is a crossroads, where Taubes ignores a plausible hypothesis in an indefensible.
The hypothesis of carbohydrates of obesity: a critical examination
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