Check me here.
Taubes proposed that carbs cause chronically high insulin levels; this ultimately causes insulin resistance and diabetes/metabolic syndrome (and associated obesity).
Guyenet more recently proposed that hormonal hunger signaling gets dysregulated in the brain by "hyper palatable" foods in the gut; this, then, is his preferred explanation for the cause of obesity.
Can both of them be correct? Is there any reason to expect that there is a single "dominant" factor in obesity?
They are both partial correct and so is Lustig......the problem is their unification. They are all making the same error in my estimation. They are starting their thought pattern distally instead of proximally. The brain, and specifically the hypothalamus, is where all the action begins.
This is why I have been critical of all three......not because I think they are wrong or nuts etc.......because they all suffer from microcosmic thinking instead of looking at the forrest thru the trees. These three guys are all in their own way brilliant thinkers. But here is the thing about experts......they lose their global view because they get so caught up in the details. You should always focus on the bigger picture first then fill in the details. And ironically this is exactly how the human brain is structured to work. Their scientific socialization has actually rendered them very to a very un paleo mindset. IE that their perspective has narrowed.
I enjoy each one and respect them for the contributions......but as long as they continue to go as they do......I hope the infighting continues. Because this is how things evolve. That is why I was so happy to see Lustig embrace leptin in the AHS talk. He still screwed it up.......but he is getting closer to the prize.
SG is clearly a brilliant thinker.....but he is focusing on outflow behavior tracts. Important yes......dominant not close. Taubes is focusing in on the peripheral part of the story.....carbs, insulin and IR at the liver and muscle levels. The main point is the integrator of all this info......the brain.
I remain confident after AHS the group that leads this society will come together eventually. This science contains this gravitational affect. All in all we all win because science wins.
I don't have time for a lengthy answer. Here is my view based on extensive reading of both Taubes and Guyenet (and a lot of KGH too)
We can debate the cause until we are blue in the face. But, everyone can agree it is multifactorial, right? On this basis I cannot accepts Taubes' continued assertion since the writing of GCBC. This does not in any way diminish my gratitude for what Gary Taubes has done to demolish the bad science and politics underlying Diet-Heart/Lipid hypotheses and the incorrect vilification of saturated fat/cholesterol.
Once metabolically deranged irrespective of the cause, the question is how to do you remediate? This is where potentially we might feel that we are at a fork in the road, though I do not view it this way. SG already acknowledged in his series (will insert link later) that Low Carbohydrate diets are effective for weight loss. He also said that Low Fat could work too. YMMV. The key difference is that Stephan is not making an insulinogenic arugment necessarily but rather than the "numbing" effect of Low Reward food that results in spontaneous reduction in calories. In this sense, if one ignores the specific biochemical mechanism, you could view Food Reward as a superset of Carbohydrate Theory.
So my bottom line
My money is on Stephan. This is not synoymous with saying Food Reward is the ONLY factor. But I have a lot more to write on this, but my stupid neolithic day job calls. TTFN...
QUICK EDIT IN BETWEEN MEETINGS -
I am primarily focusing on being overweight/obese in my response and not other derangements like T2 diabetes. If you are diabetic, then damn straight I would avoid carbs like the plague. If I had cancer, damn straight I would be on a ketogenic diet. Just want to be clear on my focus.
Regardless, at the expense of stating the obvious, the cause of metabolic derangement vs the subsequent dietary modifications to control/remediate need not be the same thing!!!
That doesn't mean the nail didn't give me the flat. Nor does this invalidate the need for different solution to seal the leak...or possibly acknowledge the tire is beyond repair.
End Lame Analogy
i think it all fits into a the way the system that regulates satiation is thrown out of wack. if we go down the rabbit hole of metabolic syndrome we find that whether we buy into the leptin, insulin or food reward camps(or a combination thereof) the remedy is most likely to be the same. if you go low carb(paleo) to regulate insulin that also does wonders for giving leptin receptor a chance to repair. if you go the route of the quilt's leptin repair protocol, whaddayaknow, it's low carb so it automatically helps with insulin. stephan's plan is a bit of an outlier in that he doesn't think the macronutrient ratios matter even in the repair phase of fighting obesity(i disagree for now but am open to being convinced otherwise) but the way in which he restricts calories through bland eating will also make sure that only a limited amount of fructose gets in the diet which also helps repair leptin receptors/sensitivity and takes out one of the main culprits of metabolic syndrome. i know there are alot of nuances that i'm brushing over but this is how i see the big picture.
i think of it like this, it's a nice academic exercise but on a practical level, when it comes to implementation, it's like arguing who the burglar is when you know the .45 in your hand will take care of whatever situation is.
Until I see people following Stephan's plan and losing weight and keeping it off my money's on Taubes. Obviously I'm hugely biases as my own weight loss which was done according to his remedy.
I also have tried the food reward thing many times over my life and while I did lose weight I could not maintain the weight loss. I can drink gruel for months on end and lose 100 lbs and yes it's pretty easy. But what then? Drink gruel the rest of my life? When does one learn how to live with real food again? For most the "food is fuel and only fuel" mindset simply does not work. Why? Because it's not! This idea may work in theory but in real-world practice I see nothing but ultimate failure in this concept. If someone else sees any sort of sustainable life to be made of Stephan's theory I'd love to hear about it. I just don't see it.
Having said that I am still seriously considering a Level 5 for a month or so. The only reason I feel comfortable is that I already know how to live with food and low carb paleo is my diet of choice and has been for years. I have nothing to learn there. I am also settled in at a very strong setpoint so I'd been a fool not to at least give this idea a try. Now I just need to get Aravind to suck it up and do it with me and we're a go. We were supposed to jump in right after AHS but he's being a wimp.
Edit: Just wanted to show clearly that SG is not a fan of LC. In fact he doesn't appear to see an issue with the effects of carbs on BG and insulin. It would in fact appear that this is a battle of SG vs Taubes. My answer still stands. Taubes for the win baby.
*Some people have lost fat simply by avoiding carbohydrate or fat. I've heard people say that a low-carbohydrate diet in particular curbs their cravings and allow them to have a healthy relationship with food again (although others have developed strong cravings on low-carbohydrate diets). I believe this is mostly, if not exclusively, driven by the fact that carbohydrate and fat are major reward factors.
I believe that all things being equal, it's best not to restrict any macronutrient to an extreme degree (there may be some exceptions, such as diabetes). That being said, as carbohydrate and fat are major reward factors, they are additional tools in the toolbox that you can use to further reduce reward if you choose.*
luckbastard already has a good answer, but based on what I learned at AHS I made this chart
it implicates hyperpalatable industrial food (high in fructose, omega-6, inflammatory garbage, easy to overeat) as the cause of the whole cycle of issues affecting us, but there is no ability to get out of the cycle by simply just removing those foods, you have to correct every single factor in the cycle in order to exit it. Low-carb dieting can correct hormonal dysregulation (though there are other ways out of that), but if you keep eating those Atkins Peanut bars and feeding into inflammation, you ain't exiting the cycle. That's why paleo is such a good solution- at its best it has the toolbox for all of the issues. I think Mark Sisson's approach really underscores that with the removal of inflammatory foods, probiotics, the "carb curve", and emphasis on whole real foods.
Not really, because they differ exactly on the crux of the issue.
"Taubes proposed that carbs cause chronically high insulin levels; this ultimately causes insulin resistance and diabetes/metabolic syndrome (and associated obesity)."
Stephan has specifically stated that he does not agree with this.
It's possible to eat enough carbohydrates that insulin becomes elevated all day long. All of the low intensity activity that you do in a day, whether it be walking the dog, washing dishes, gesticulating (like Stan of Stan's Previously Owned Vessels) etc. etc. would by default be powered by muscle mitochondria with an energy substrate comprised of lipids. We have a massive store of these lipids, whereas glycogen is relatively sparse and precious for CNS/organ fueling and emergency high intensity activity. If your body is constantly having to cope with rapidly-digesting, high glycemic carbohydrates, you encounter a blood sugar emergency where some of it has to be dumped into the mitochondrial furnaces because glycogen repletion simply can't occur at that rate (and you simply don't have the capacity to store it all even if it did). You'd still have times where you're burning body fat, but they would be greatly minimized. Meanwhile, the long-chain fatty acids you're ingesting are making their way into your adipocytes and you get somewhat of a one-way-street effect.
That all being said, I think it's unlikely that consuming starch alone is enough to become obese. It's absolutely enough to halt fat loss however. Now, if you add massive doses of fructose and the subsequent hepatic (and later muscular) insulin resistance, then you end up with a constant one-way-street effect. Lipolysis may simply never be occurring to any significant effect. If you add inactivity, then muscular insulin sensitivity is never restored. With a high intake of those LCFAs alongside your high carb and high fructose intake, you're packing those adipocytes continually. Some amount of the fructose itself would be converted to FAs via DNL, but I think that fat is largely concentrated around the liver, though a threshold might be crossed whereat these FAs are shipped around systemically.
If, on top of all of that you add hyperpalatable foods, and the addictive behaviors they create/support, you have a perfect storm for obesity and non-insulin-dependent diabetes.
My assumption is that there is infinite variability in the ratios of factors contributing to any given case of obesity but that these are generally at least present in some way. I'm sure there are other, lesser factors, such as inflammation at play as well, but I don't think they approach the importance of these. I don't see any reason why all of these three things can't be addressed simultaneously for a fat loss protocol with maximal efficacy.
Although I don't buy the bland diet hypothesis that Stephen puts out, there's definitely more to weight loss than just cutting carbs. Has any one read the mediterranean versus paleo diet study?
Of course, Paleo diet beat Mediterranean in terms of weight loss (especially fat loss as measured by lost inches in the waist line) and all other areas as well.
That's no surprise, here's what REAL shockers for you low carbers, the macronutrient breakdown of both diets were IDENTICAL. Yes, they upped the carbs for the Paleo diet so it matched the mediterranean, yet paleo dieters lost more weight.
WGA, excess omega-6, and other non-paleo nasties all increase insulin resistance.
Yea I'm sure if 90% of your diet is liquid glucose then you're probably gonna gain weight. Point it's more than just blood sugar spikes and glycimic index that Taubes and company blame.
I think they're both wrong. Taubes is obviously wrong because there are high carb societies who do just fine. As does anyone who manages their insulin well, no matter the macros. And Guyenet is wrong because there are plenty of people who eat taste-intensive foods and are in great shape. Hell, I can do that now. So while I have no doubt that Stephan has a point about palatability having an effect, it only becomes relevant if you're a contest-shape bodybuilder or want to get down to sub 8% bodyfat. I feel it entirely unnecessary for people to get fit and lean(10%men, 12% women) and/or not disregulate insulin. Regular whole foods diet and weight training will do it just fine for the overwhelming majority of folks.
I think they are both somewhat right, but I also know plenty of people (I know, N=1 + N=1 + N=1 still = 0 for many people....) who do not have the same experiences. While it may be true that many people who have been resistant to weight loss on CW have success on a low carb diet, it does not follow that the carbs caused the condition. Likewise, while it may be true that tasty food does dysregulate things and cause problems, removing the tasty food won't necessarily fix the problem. I know lots of people who stall out on a low carb diet, so it cannot be the complete answer, unless you believe, like many, that the continually-fat people are lying to themselves, cheating on their food diaries or something like that. And, I know plenty of N=1's who not only currently have a bland diet, but they also know that they would eat pretty much anything to get their carb fix, palatable or not. This includes eating lots of dark meat to squeeze out the glycogen, etc. One other thing I will say about certain plans is that it is not productive for some experts (like Wolf) to say something like, "hey, this program works 100%, and if it doesn't, then you are doing something wrong." People don't succeed on certain plans because the plan does not work for all people. They should be tinkering with the plan instead of blaming the people. While I think that Taubes has a better solution to obesity and Guyenet has a better cause, Quilty wins on the whole package.