I was super excited to listen to the debate on the Joe Rogan Experience between Stephan Guyenet and Gary Tabues. But, as anyone who has listened to the episode knows, it got pretty bogged down in personal animosity and didn’t have a lot of great content.
Taubes is a science journalist known for his tome “Good Calories, Bad Calories” and is a low carb diet advocate.
He posits that obesity is caused by dysfunction of the storage process of body fat – which is mediated through excess insulin secretion. He also argues that energy is “partitioned” more favorably to body fat in high carbohydrate diets. Through these arguments, Taubes also attempts to discredit the current science of obesity research, which has settled on a largely “brain-based” model for regulation of body fat stores.
Stephan Guyenet is a neuroscientist, researcher and author of “The Hungry Brain” – as well as a former guest on my podcast.
Guyenet’s model of body fat regulation focuses on the brain – with a hormone called leptin being the primary modulator of energy intake and expenditure through interaction with the hypothalamus.
While both Taubes and Guyenet agree that body fat storage is a complicated interplay between central regulation (through the brain) and peripheral regulation (through the actual mechanics by which flux is mediated in and out of fat cells), they come to different conclusions surrounding which of these is the dominant player in terms of controlling body fat stores in individuals.
While this may seem like an academic debate or like something that’s “deep in the weeds,” I find that this type of information is surprisingly impactful on the actions of every day folks trying to lean out, look good and feel good.
If my biases aren’t clear, I’m very firmly in the same camp as Guyenet and I think that the carbohydrate model of obesity has been pretty thoroughly discredited.
But, as a CrossFit gym owner and a coach, I am regularly interacting with people who are eating carbohydrate-restricted diets while engaging in high intensity training – which I think is not just a potential impediment to their progression over time, but also a health hazard based upon the demands on the system of a difficult training program.
So, the vague notions floating around about insulin, carbs and keto do have an effect on real people, and I think it’s important that the conversation in the fitness subculture change to recognize the actual state of the science.
Insulin is obviously a key aspect of body fat storage – no one who has read a text book on metabloism would dispute that.
However, the key aspect of body fat regulation is not just the mechanism by which energy is either stored or released from body fat.
Instead, it’s the entire flux of energy relative to the organism. This flux is controlled by our hunger – which is modulated by a complex series of factors including leptin signaling, NEAT (non-exercise activity thermogenesis), inflammation in the hypothalamus, sleep (which has a direct effect on impulse control), and the reward/palatability of the food in our environment.
This is not to say that low carbohydrate diets are ineffective. For many individuals, low carbohydrate diets result in significant body composition changes. These changes, however, are probably not due to the exact mechanics of insulin signaling. Instead, they work by:
•eliminating a huge percentage of hyperpalatable and highly rewarding foods (aka “junk food”)
•creating rules and awareness surrounding food consumption (almost any intervention that brings awareness and accountability to consumption results in body composition change)
•causing a reduction in overall calorie intake by restricting significant numbers of commonly consumed foods
•increased satiety through increased protein intake
And, in individuals with significant insulin sensitivity issues or altered glucose metabolism, restricting carbohydrates can be a crucial aspect of regaining blood sugar control.
So, as a coach, it’s not that I’m opposed to low carbohydrate diets. I am opposed to a lot of the mythology that surrounds them, though, since I think it pushes a lot of people toward unsustainable attempts at lifestyle change.
For more info from Dr. Guyenet, I wouldn’t recommend listening to the Rogan show, but I would recommend checking out these resources:
•Why the carbohydrate-insulin model of obesity is probably wrong
•The Carbohydrate Hypothesis of Obesity: a Critical Examination