February 22, 2010
The response to the written version of my 2013 AHS presentation has been overwhelmingly positive. Based on page views, the number of people willing to read my work greatly exceeds the number of people willing to watch it in video form!
This is some of my finest work. It provides a theoretical and practical framework for understanding hunger—an understanding sadly obscured by oversimplification and moralizing, from both scientists and policymakers. This is doubly unfortunate because the science…
I am not sure how you show the slide 3 data from your theory.
It was only used to discard the others.
Also junk food relate to empty calories your main result.
So I am not sure how you say that its not junk food.
In the palatability model, junk food has an excess of an intrinsic property called "food reward" that causes us to overeat it. As the table shows, junk food was not invented in 1979, so that hypothesis fails.
However, you raise an excellent point, which is "Did junk food consumption increase after 1979? If so, why?" Data on this is somewhat squishy, but let's assume it's true -- at which point we must invoke the present model of hunger in order to explain it! Otherwise there's no way to explain why Twinkies had less "food reward" before 1979 than afterward.
Yes there is a 20 years delay, but the graphs look remarkably similar in slide 7.
Couldn't it be that it takes 20years for the system to get metabolically damaged to start gaining fat.
Perhaps -- but then we're back to the present model of hunger, because you have to explain why McDonalds food was both fattening and "rewarding" in 1990, but not in 1970. (Note that the Super Size meal didn't exist until perhaps 1994...long after rising obesity was an established problem. And 1994 was when year-over-year spending on fast food actually decreased for the first time in decades!)
This is indeed possible under the present model -- but I prefer to begin with hypotheses that don't require a 10+ year delay between behavior and results. I'll be exploring some of these in the future.
[Note: I'm experimenting with the Tom Naughton style of responding within the individual comment, instead of in a block later on. Let me know what you think!]
Yes this was superb! Thanks J.
Thank you! I'm glad you find it helpful.
J, in less than a half-hour you managed to tell laypeople, in clear concise language, what most MDs fail to understand. your contribution to the nutrition field is outstanding. thank you! [dashing off to post a link on facebook....]
The "sloth and gluttony" model of hunger is extremely seductive -- especially for people who are naturally skinny, a property naturally common to the social class and personality type of people who tend to get MDs.
And CICO is also seductive because IT'S PHYSICS!!!11!!1!, but it's also unhelpful. Telling fat people "All you need to do is eat less and move more, fatty" is like telling a losing sports team "All you need to do is score more points, losers."
So the question is, are the rats eating the sugar in a blind attempt to get more micronutrients, or do the rats actually get something they need from the sugar because the lack of micronutrients causes something.
Great question! I suspect it's a combination of factors.
First, the rats probably have less efficient energy metabolism at some level due to lack of micronutrient(s), and eating more sugar compensates for that.
Second, the rats might not be getting anything they need from the sugar -- but refined sugar is evolutionarily novel, so the rat "thinks" it's getting fruit or some other naturally sweet substance that does contain the nutrients they need.
I've said for years that the reason we have "a sweet tooth" is that our bodies are craving the vitamins that are in fruit. The trouble is we've reprogrammed ourselves into thinking that when we want something sweet, it is empty sugar calories we should have. Our bodies are craving Vitamin C, for example, but we end up eating orange candies instead of oranges, because when we saw them at the store, for some reason that orange flavor just sounded really good.
I think this is the same thing when it comes to the rats; not enough vitamins in their diet, so they crave sweets, and eat whatever sort of sweet is available.
Great to see you again! It's been a long time. (Cornelius is one of my OG readers and commenters.)
I agree with your point about fruit, btw. As I said to tam, refined sugar is evolutionarily novel...and you'll note that plain sugar actually doesn't taste all that good! Candy and soda is almost inevitably fruit-flavored.
I think it was Paul Jaminet who noted that sugar and starch (particularly sugar) were probably rare during the Paleolithic because we don't seem to have an "off switch" for their consumption: they don't satiate us the way that meat does, even though consuming them to excess is definitely harmful. (In a time without toothbrushes and dentistry, high-fruit and high-starch diets rot the teeth, which is a massive survival disadvantage.)
The implication is that we couldn't have had access to them in excess, or the ability of sugar and starch to satiate would have been selected for -- just as it was with meat.
So what *did* happen in 1980 to cause those inflection points?
I'll be exploring that question in future articles.
Note that it's taken me years of research to get to the point where I'm comfortable advancing my own hypotheses! It's a complicated problem, and a monumental amount of "big picture" knowledge is required to avoid the typical pitfall, which is attempting to explain the entire system in terms of the small part you understand.
February 22, 2010
I'm experimenting with the Tom Naughton style of responding to my readers, where I add my reply at the end of each comment instead of aggregating them in a new comment. Let me know what you think!
The Tom Naughton commenting style is fine for a moderated blog, where the comment and response are posted at the same time. But, editing people's posts, after they've already been posted, is really annoying. That means people reading on the website have to keep going back to see if you have added any responses. And, on RSS readers, your responses don't show up at all because all that shows up is the original post, without the added comment. For someone who just shows up to visit and read, long after stuff has been posted, your responses flow beautifully. But, for regulars who are active here and try to follow along chronologically as it unfolds, it absolutely and completely screws up the flow of the conversation.
Point taken. The only other way I can think of to make it work both ways is if I go to threaded comments, which have their own issues. I'm still seeing how this shakes out, as opinions are divided.
Well, the theory is compelling. Unfortunately, most of the time, eating better does not lead to (substantial) weight loss. I believe that is a well-established reality.
I have heard of a few people who used to eat junk food and drink beer 24/7, and lost their surplus weight when they just started eating reasonably. However, those are the exceptions. Most obese people eating healthy food to satiety (well, satiation I guess) will stay fat. For instance, people who embark on the 100-mile challenge (eating locally for one year, thereby eliminating all junk food) do not become slim as a result. It seems that as soon as you start dipping below your highest established weight, hunger seriously picks up, and you end up eating enough (non-junk) food to maintain if not regain weight.
You've touched on something very important which I mentioned several times in the talk, but didn't have time to explore in-depth due to the 20 minute limit. Recall this quote:
"Satiety: Our body’s nutritional and metabolic state. It includes both our biochemical response to the absorption of nutrients, and our access to stored nutrients."
The "access to stored nutrients" part is where this ties in with your experience, and that of many others.
I first mentioned this as an important driver of satiety all the way back in 2011, with Part IV of the original article series, but I've expanded on it at great length: my entire AHS 2013 presentation is about metabolic flexibility, which includes access to your own fat stores as well as ingested dietary fat. (To that equation we can add leptin dynamics, which also impede access to stored energy.) These two dynamics explain the reduced metabolic rate in the weight-reduced obese, as well as their continual hunger.
Also recall that many obese people are still gaining weight…so simply becoming weight-stable via improving one's diet is a dramatic improvement. And for those who aren't already obese, even small improvements in nutrition can have very dramatic effects, because they're not fighting leptin dynamics.
(An aside: a relative of mine is counting calories for the first time because he just went through surgery, lost a lot of lean mass, and needs to gain weight — and he's said many times "It's really difficult to eat 2000 calories a day without eating bread or junk food!")
So yes, nutrient content is not the only factor at play. Access to stored nutrients is the other major factor — but given time constraints, I had to wait until 2013 to talk about it!
Funny. I was just watching the video of this a few days ago. I probably watched it the first time about a year ago. Definitely better the second time around. It was quite a surprise to see this headlining your blog tonight.
The main advantage of the video is the Q&A afterward. Seth Roberts and Stephan Guyenet and a woman I don't recognize (nor know if I should).
In your response to Larry you mention the years of research that precede a presentation like this. It's got to be a bit frustrating to know you have a nice coherent 20-minute summation of what you've learned while there was probably nothing coherent about the learning. It looks deceptively simple, as though anyone could spend a few hours at the library and knock something like this out.
A bit like the Gnoll Credo: "We all know this…"
I think I like your new approach to comments. I don't have to scroll up and see what you're responding about. I just hope you don't fall into the trap of thinking you have to respond to every comment (like this one, for example).
The third questioner is Melissa Hartwig, of Whole 30 and "It Starts With Food" fame.
It's difficult to think on one's feet! What I should have said to Stephan was "Yes, palatability drives consumption to some degree -- but as the presentation proves, it's a subjective property, and therefore a second-order effect. So the interesting question is 'What's driving palatability?'"
Thank you for noticing the work I do. In general, the better someone's understanding and communication ability, the less impressive their discoveries sound. "Of course, it's so simple." Well, it wasn't simple until I explained it!
And thank you for tying this in with The Gnoll Credo. The book itself speaks far more eloquently than anything I can say about it.
Thanks for posting this. There were things in this article that I don't remember from the video or from your earlier series on the subject. Which either means my memory is faulty (likely) or that you have added new material, or you've simply presented it in a slightly different manner that resonated with me more.
So, referencing an earlier article you wrote, it seems we have two distinct problems. One: how we got fat. And secondly: how do we lose the weight. I' m not sure this article adequately adresses the first problem, but, if I understood correctly, the answer to the second problem is to eat a nutrient dense diet which will produce satiety and end incessant cravings and hunger.
In regards to the first problem of how we got fat I wonder if there is a tiping point. I seem to remember that Weston Price did experiments on cats where they could eat up to 20% junk food and still remain healthy but beyond that all kinds of bad things happened. Maybe we didn't get metabolically broken and obese during the 60's and 70's because we were still eating enough real food to protect us from harm.
The article is exactly as I gave the speech — with the exception of a few notes to the reader, enclosed in braces , and the note on positive vs. negative satiation, which I removed due to fear of the time limit. It's much easier to remember lists when they're presented visually, not verbally!
You are correct: "how we got fat" is not necessarily the same problem as "how can we get slim again?" And as I pointed out to Valerie above, our body's access to stored nutrients via metabolic flexibility is just as important as the nutrient content of our diet…but there was no way to cover both topics in 20 minutes, so met flex became my 2013 presentation.
My current research suggests that several things need to happen in order to 1. cause weight gain and 2. leave us unable to lose the weight we've gained. Having one isn't enough. And yes, nutrient deficiency is one part of that puzzle.
February 22, 2010
Thanks, everyone, for your support and comments! I'm now caught up.
Thanks for your response.
But my crucial question still stands. How do you explain the data of slide 3, with your theory.
I maybe missing it in the slides. Could you point it out.
By slide 3, I think you mean the graph of obesity over time…so if your question is "So what caused the obesity epidemic?" I have to repeat that I'll be exploring that question in future articles.
What I'm presenting here is the best model we have for thinking about these sorts of questions. So my thought process goes something like this:
The data says that our food consumption increased roughly in parallel with our weight, both starting around 1980 (see this article). Why is that?
Well, according to this model of hunger and consumption, one or more of the six factors I enumerated must have changed.
I see no evidence for a nationwide failure of willpower, and incentive salience is mostly a product of the other three hunger factors, so we're looking at some combination of hedonic impact, satiation, satiety, and the modifier of availability.
I don't see good evidence that hedonic impact has changed dramatically, because all the classic junk foods and fast foods were well-known and widely advertised before 1980. (See Slide 5, "Junk Food Invention Dates") It may be that we're consuming more of them, but that still begs the question of "Why?" — so we must turn to satiation, satiety, and availability.
And once we recall that satiety is "Our body’s nutritional and metabolic state. It includes both our biochemical response to the absorption of nutrients, and our access to stored nutrients," we have a theoretical and logical framework by which to attack the problem. To wit, how did the changes in our dietary and life patterns since 1980 affect these factors?
As I said to Larry (and to Seth Roberts in the Q&A), it's taken me years of research to get to the point where I feel comfortable advancing any hypotheses. If obesity were a simple problem amenable to solutions beginning with the word "Just" (e.g. "Just eat less and move more") we'd have solved it by now!
So is Stephan Guyenet saying the opposite?
No, he's opposing the specific contention that micronutrient status can affect food intake.
Let me be clear: that isn't the sole point of this presentation! I used it as one specific application of the modern framework for understanding hunger in terms of the four motivations -- satiation, satiety, hedonic impact, incentive salience -- and the two modifying factors of availability and willpower.
However, I'm not impressed with the scholarship in his article. (All linked references are from my bibliography.)
1. Stephan handwaves away the results of Li 2010 by saying "I found this result difficult to accept uncritically," strongly implying that there are dozens of studies disproving it -- while failing to present any of them.
2. I presented the results of Major 2008 as follows: "If calories are held constant, weight and fat remain the same, but the placebo group experiences greater hunger than the multivitamin group." This is exactly the result you'd expect if micronutrient status affects appetite, because calories were held constant!
Also, Stephan stated that only fasting appetite was affected. Quote: "Fasting and postprandial appetite ratings were significantly reduced in multivitamin and mineral-supplemented women (P < 0.05)."
3. Stephan conveniently "forgets" to discuss Major 2009, which I'll quote here for emphasis: "The calcium+D supplementation induced no statistically significant increase in fat mass loss in response to the programme. However, when analyses were limited to very low-calcium consumers only (initial calcium intake < or =600 mg/d, n 7 for calcium+D, n 6 for placebo), a significant decrease in body weight and fat mass (P < 0.01) and in spontaneous dietary lipid intake (P < 0.05) was observed in the calcium+D but not in the placebo group."
4. Stephan also fails to discuss Davis 1976 -- the rat study that showed greatly decreased voluntary sugar intake from supplemented rats.
5. Stephan states flatly that "Another problem with this hypothesis as an explanation for obesity is that modern Americans have relatively good micronutrient status by global and recent historical standards. Although we may not eat an optimal amount of all micronutrients, frank deficiency is uncommon, in large part because much of our food is fortified."
However, Stephan does bring up a point I discussed long ago in 2011: our sensing of nutrients is usually indirect. We don't taste complete protein: we taste free glutamate. We don't taste Vitamin C: we taste fruit-flavored sugar. And so on. So it's quite possible to fool our "nutrient sensors" with modern, processed foods that taste as if they ought to fulfill our nutrient needs -- but do not.
He seems to believe this disproves that micronutrients can drive hunger, but a moment's thought will show the opposite. If we didn't have a strong need for the nutrients in those foods, we wouldn't crave the foods that taste like them (but aren't). For instance, almost all candy is fruit-flavored: plain sugar isn't actually that tasty.
As Cornelius points out above, fruit has several interesting nutrients in it (particularly Vitamin C) as well as sugar calories...therefore we prefer fruit-flavored sugar to plain sugar. Our tastes and instincts don't know about allyl hexanoate: they only know about pineapple.
Result: My points stand.
In closing, let me reiterate something I've said several times before: this is not a personal conflict, and I would appreciate people not making it into one.
personally i love the answering queries in the question block: often if you don't get on the blog for 2 days there have been 30+ comments and then i have to scan up and down all the comments to see what your response is actually to/about.
as to the rats/humans eating sugar is this simply because part of breaking met flex that we cannot access stored fat and also using fat for fuel, even dietary fat, is just harder.
The rat/micronutrient experiment is extremely interesting, and it poses many more questions than it answers. I don't know if the smaller supply of micronutrients impairs the utilization of fat, increases obligate glucose demand, directly affects incentive salience in the brain, or what's going on. More experiments along these lines are clearly needed...but vitamin research is all but dead because there's no profit in it. You can't patent vitamins.
glucose is a simple fuel that the entire body can use all of the time, so we eat it if we're metabolically broken because it can (but not definitely does) become the only fuel we can use.
(we always have some level of fatty acid oxidation, but it becomes harder? just to be clear for knee jerk reactionaries)
Metabolic inflexibility means that you're stuck burning some of both regardless of conditions. When you're fasting, you have a big obligate glucose demand, so you get hungry more quickly: when you eat starch or sugar, you can't control your blood sugar as well because you can't increase glucose oxidation to help dispose of it.
this makes sense to me. i have some friends i've offered advice to about weight loss. including starting the day with no carbs (starch/sugar) to upregulate fatty acid oxidation and help with insulin/leptin dynamics. but they've always said they just don' feel full, but eating some carbs makes them full for longer: is this just because the fat they eat isn't accessible even though it is dietary and not stored?
Remember, it's not that the fat isn't accessible: it's that they've got a continual demand for glucose they have to meet.
even big names in bodybuilding and sports performance now are leaning towards red meat, vegetables and nuts for breakfast (charles poliquin, ben pakulski, ultimate performance gym to name a few i follow) even in fact for performance, not just fat loss.
Those guys aren't afraid to experiment. And performance is easy to quantify in the fitness field: you lifted X and/or did Y reps, so you get good feedback on the impact of your choices.
also "Telling fat people “All you need to do is eat less and move more, fatty” is like telling a losing sports team “All you need to do is score more points, losers.” "
had me in stitches, may in fact be a facebook update i think!
Readers are always encouraged to help make more gnolls.
I liked this a lot. Clear, concise-ish and included a small rant on the usual suspects, which I personally enjoy.
Being limited to a 20-minute presentation enforces a certain economy of phrase and style.
I usually don't cut loose like that -- but AHS2012 had a big public policy focus, and I wanted to make it clear that paying farmers to grow grains and then taxing the artificially cheap products of the resulting grain surplus is a) crazy, b) ineffective, and c) tinkering around the edges of the real problem.
Besides, I love the phrase "passively compliant grain disposal units"!
Wonderful. You may be the best nutrition writer working today.
And count me as another vote for the integrated ("Naughton-style") comments. They work incredibly well for me.
(And I suspect your html audience is at least 10 or 20x the size of your RSS one.)
Thank you! It means a lot to know that I've successfully communicated my insights to others.
The best thing you can do in return (aside from buying a copy of TGC, if you haven't already) is to let more people know about gnolls.org by forwarding my articles to other people.
Yes, this style of commenting is better. I think it's better for everyone else, too.
Thanks for the feedback!
“It's really difficult to eat 2000 calories a day without eating bread or junk food!”
I'm always surprised when I hear this. I find it extremely easy to eat thousands of calories worth of fat daily, especially in the form of cream/butter (in coffee and tea) or say peanut butter (a whole jar straight, no problem). Not sure if that counts as junk food (peanut butter is high-oleic so minimal o6). Btw, I'm sedentary and do gain rapid weight eating SAD, but not so much with the above mentioned foods. My mainstay is fatty meat, so I habitually eat perhaps double the amount of calories that would see me gain weight eating high carb SAD.
I didn't know you could even get high-oleic peanuts! I looked into it, and apparently they do exist. They're not GMO either: they're the product of conventional breeding. I don't eat them, though, as they're legumes and off the Paleo template -- though a high-oleic version would make them less of a cheat. (Actually, high-oleic peanut oil would be nice to have, for occasional Asian cooking.)
First, the person I'm talking about is well along in years, so their average daily energy needs are likely quite a bit less than yours. 2000 kcal is a substantial step up from their usual food intake.
Second, I would have to add "bread, or junk food...or guzzling isolated fats." I can easily drink a half-gallon of half-and-half in a day (~2300 kcal, if I recall correctly). Um, yeah, don't do that! Many people find, as do you, that it's almost impossible to gain weight on keto (see my calorie series, Part VII) -- but as I noted in Part V of my original hunger series, eating more quickly often causes one to eat more, period. And one can drink much faster than one can eat, so why tempt fate? Unless you're going to be exploring the Arctic and need the extra thermogenesis...
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