Indeed, it's a review by someone with an axe to grind about a book by someone with an axe to grind.
I'm not a "Paleo" person, but the hinting in this article that folks trying to infer better living patterns from the past are loons is faintly preposterous. We have just mounds of evidence (which doubters are free to research themselves) that many pre-Agricultural societies had (and have, actually) far lower rates of the so-called "diseases of civilizations". More abstractly, evolution isn't magic. There is some rate of lifestyle change due to technology that will outstrip evolution's ability to accommodate it.
Hunters and gatherers weren't obese. We are. By irrefutable inference, some lifestyle difference explains this. One valid way to approach the problem of our accelerating obesity is to study what has changed. The theory that I consider most likely at this point is the one argued by Stephan Guyenet, a PH.D. neurobiology researcher who studies the link between obesity and the brain. He posits that modern industrial food is hyperpalatable, so we eat too much of it.
> Hunters and gatherers weren't obese. We are. By irrefutable inference, some lifestyle difference explains this
Yeah and that difference is the sheer abundance of cheap calories. People can and did get fat when eating too many calories of Paleo (easily possible if you overemphasize the fatty meats and sweeter fruits), people can and did lean out on breads and junk-food by simply consuming fewer calories than they expended over a prolonged period.
I have no axe to grind here, I'd say I myself eat 99% Paleo 99% of the time, save for the occasional brownie. Otherwise it's meats, vegs, fruits for me. But that's just my personal taste, and for body-fat storage or lack of it, consuming in excess of your energy expenditure surely must account for most of the most of it.
It's not even the Paleolithic that had a 'better' diet; sugar production in industrial quantities didn't happen until the 19th century and High Fructose Corn Syrup [1] didn't become a staple of the human diet until the second half of the 20th century.
> High Fructose Corn Syrup [1] didn't become a staple of the human die until
AFAICT HFCS didn't become a staple of human diet, it just became important in the US, the rest of the world still uses _way_ more sugar than HFCS (e.g. a 60:1 rate of production in the EU).
Not really. There's a pretty clear connection between insulin levels and weight gain. Spiking your insulin levels by eating carbohydrates will effect how calories are used for many if not all people.
I'm not denying that there certainly are such factors at play at some level, but not sure how decisive they are: I'd wager they won't make a dent if you consume 4500 calories of Paleo a day, and likewise won't if you consume 1200 calories of junk-food a day -- say for the average non-athlete rather-sedentary adult.
There's a reason Atkin's diet is so popular. It's because it's extremely effective at shedding weight. Sure there might be a point at which you're gaining weight due to the fact that it's an astronomical amount of calories and there are going to be differences in biology but over-all people find eliminating carbs will cut the weight even if they don't cut calories.
"Successful weight loss can be achieved with either a low-fat or low-carbohydrate diet when coupled with behavioral treatment. A low-carbohydrate diet is associated with favorable changes in cardiovascular disease risk factors at 2 years."
"Data from several randomized trials over the past 6 years have demonstrated that low-carbohydrate diets produced greater short-term (6 months) weight loss than low-fat, calorie-restricted diets (1-5). The longer-term (1 to 2 years) results are mixed."
"Implication: Overweight persons can achieve substantial weight loss at 2 years if they participate in a behavioral intervention combined with a low-fat or a low-carbohydrate diet."
Also, attrition rates were about the same between the two.
One of the primary arguments of a keto/paleo diet is that the different diets affect how many calories your body thinks it needs, how it uses them, and how it influences behavior as a result. (Disclaimer: using imaginary numbers below to illustrate the theory.)
Let's say your body typically wants 1000 calories at breakfast, and you eat 1000 calories with a heavy load of carbs. Carbohydrates with a high glycemic index cause your insulin to spike. That signals fat cells that they should start storing energy, and they do so, tucking away 300 of the 1000 calories you ate.
This means your body only gets to spend 700 of the 1000 calories you ate, and as such, it says "hey, I'm still hungry". You eat 300 calories worth of food. But your fat cells are still sucking up (X%) of what you eat into storage, due to the insulin reaction. So, your body gets 200 of those 300 it wants, and it stays a little bit hungry. (Or, more likely, your body wants 300, but you eat 500 to make it shut up.)
Carbs have the unfortunate habit of converting useful calories into fat storage prior to processing them for the purposes of nutrition. This means carb-heavy diets tend to cause unconscious overeating, and also constant feelings of hunger/cravings/etc.
One of the advantages of a paleo/keto diet is that they often avoid the type of carbohydrates that cause this problem, namely ones with a high glycemic index. This means when you eat 1000 calories, your fat cells don't skim any off the top before your metabolism gets to them, and you get the full 1000; this means you don't end up hungry after a meal, and don't suffer from the urge to snack/eat more. Because your body got all the energy it wanted, it doesn't start saying it's hungry again until it actually does need the nutrition, and you're more likely to eat closer to the correct amount for your body's needs.
The difference between the examples you give, 4500 of Paleo and 1200 of junk food, is primarily how they'd make your body react. 1200 of junk food would certainly be a caloric deficit, but you'd be ravenously hungry at that level. (I've done 1000 calories a day for 6 months straight - it's pretty awful for the first few months.) But with keto, you could eat 4500 calories in a day, but you won't want to. When I'm done eating a keto-style meal, I am completely uninterested in food until the next. Those meals, for me, are typically 1-2 small/medium brats with no bun. But if I go out and cheat, and grab a burger and fries, I've got to fight the urge to follow it up with some ice cream, even though the fries and burger combined are drastically more calories than the brats I was satisfied with the meal before.
It's really interesting stuff. The "calories-in, calories-out" model is completely right from a completely energy-based perspective, but it doesn't account for the side effects produced by the energy source, and how people react to them.
This is pseudo science, there are droves of scientific literature that shows that meal timing is irrelevant and that as long as macronutrient content is similar, a calorie is a calorie.
And there are droves of scientific literature that show that meal timing is important and even if macronutrient content is similar, a calorie is not a calorie.
The simple fact is: No one was able to prove anything beyond shallow platitudes ("If you eat three tons of flesh each day you will get fat too!" "If you eat nothing for month you will get lean!").
A quick search of PubMed finds some recent (within the last year) papers like:
http://www.ncbi.nlm.nih.gov/pubmed/23357955 - "Timing of food intake predicts weight loss effectiveness" It starts "Background: There is emerging literature demonstrating a relationship between the timing of feeding and weight regulation in animals. However, whether the timing of food intake influences the success of a weight-loss diet in humans is unknown."
http://www.ncbi.nlm.nih.gov/pubmed/23167985 - "Effects of exercise before or after meal ingestion on fat balance and postprandial metabolism in overweight men."; "It is unclear how timing of exercise relative to meal ingestion influences substrate balance and metabolic responses."
These make me think that there isn't "droves of scientific literature" which show the importance of meal timing in humans, much less characterize the magnitude of the importance. (Eg, if there's a measurable 1% difference in overall effect on weight then it's statistically significant finding, but almost certainly not enough for most people to care about.)
Where is the parent saying anything about meal timing? It's about the effect on your body of a particular meal. Carbs and sugars spike insulin much more than fats or protein.
That is an issue of meal timing. Individual meals doesn't matter. Transient insulin spikes are irrelevant, what matters is your overall expenditure vs intake.
Insulin spikes are completely relevant, since insulin signals your fat cells to take up energy from your blood stream. Now you have no energy and feel hungry again.
It doesn't work that way. Show me a study that concludes that blood glucose levels have not been meaningfully increased after a meal due to it all going straight to adipose tissue -- in humans -- and I'll show you the next Nobel Prize winner.
Insulin spikes are irrelevant in so far as you will lose weight at a calorie deficit, insulin spikes or not. Also, fat can be synthesized in the absence of insulin spikes. http://www.jlr.org/content/30/11/1727
Physiologically, what matters is a caloric deficit. Execution wise, some foods make this easier than others, but that is highly individual.
Steady levels of insulin make it much easier to maintain a caloric deficit. If your blood sugar is yo-yoing all over the place, you're going to get cravings, increase your risk of bingeing, etc.
While it's easy to fall back on 'calories in, calories out', weight loss has much more to do with psychology, physiology and compliance than physics.
You're absolutely right that losing weight has a lot to do with psychology, and that the execution of it depends on finding a method, a diet tailored to the individual's needs, to succeed.
But that diet will only result in weight loss if there is a caloric deficit, completely independent of insulin spikes. Now, the trick to achieving and maintaining that caloric deficit over a period of time is an effort that is psychologically demanding, absolutely. But the weight loss itself is pure thermodynamics.
If your interest lies in designing diets or meal plans that help people achieve their weight loss goals, your focus should rightly be the psychological aspect of it. That's the battle. But at the end of the day, a caloric deficit is necessary, whether you choose to ignore that or not.
IMHO, diet and nutrition is confusing as hell to the average person, and hiding the necessity of a caloric deficit and instead talking about "good" and "bad" foods or macronutrients, is a poor approach in the long run. But that's just my opinion. The necessity of a caloric deficit is not opinion though, it's cold hard scientifically proven fact.
> The necessity of a caloric deficit is not opinion though, it's cold hard scientifically proven fact.
It is not that simple. If you have a calorie deficit but aren't getting enough nutrients you will get cravings but won't be able to sustain your diet. If you're addicted to sugar you will get cravings/constant hunger and won't be able to sustain your diet.
Focusing on calories ignores all of the other things (nutrients, insulin, blood sugar, motivation) that need to happen for a diet to be successful.
> It is not that simple. If you have a calorie deficit but aren't getting enough nutrients you will get cravings but won't be able to sustain your diet.
That makes no sense. In that case, you aren't on a caloric deficit. If you aren't able to achieve a caloric deficit, then you are not on a caloric deficit.
There's a pretty good chance this is an over-analysis.
A daily 50 Calorie excess stacked up over 5 years amounts to a gain of about 25 pounds.
So it is certainly possible that a diet could be subtly tipping metabolism in the wrong direction, but between a complex explanation of more calories being stored as fat and a simple explanation of slightly too much consumption, I like the second one.
I guess that it is easy to consume large amounts of carbs makes them a frequent component of weight gain.
Without having done much research I also find it easy to imagine that the sedentariness of the paleo-people where, on average, a lot less than of people nowadays.
Can't say something like "(which doubters are free to research themselves)" and follow it up with a claim like "many pre-Agricultural societies had (and have, actually) far lower rates of the so-called "diseases of civilizations."
Actually you shouldn't even want to as there's a certain problem with gathering data on populations that lived 10,000 years ago with a geographically dispersed sample size of ... oh, I don't know, single digits?
This information does not just come from fossil records but also from studying living specimen, who still exist in the world today. The article mention that those people also had time to evolve, but I don't think that is much of a killer argument. Then the question would still remain (speaking of diet, which is only one aspect) why they were able to adapt to their diet and we weren't able to adapt to our diet.
> Then the question would still remain (speaking of diet, which is only one aspect) why they were able to adapt to their diet and we weren't able to adapt to our diet.
I think perhaps the point is that there isn't evidence that we haven't been able to adapt to our diet.
We have certainly adapted to an extent, but not enough yet. Proof: civilization diseases do exist. (Not necessarily all about diet, but general lifestyle compared to traditional societies).
The fact that these diseases exist shows that we haven't adapted to not have them.
Obesity is the result of a caloric surplus. Cavemen didn't have that luxury.
Obesity epidemic is a very recent phenomenon. Are you arguing that there were no societies that had caloric surplus up until late in the XX century?
Or would you say that American Samoa with obesity levels of 70% [1] somehow have the luxury of having calorie surplus, while people of Switzerland (8.2% obesity) are struggling to get enough food?
Speaking about Paleo diet in particular, why don't those guys gorge themselves into obesity [2]?
The Kitavan people have been under greater study for their remarkable health characteristics. The people show no indication of coronary heart disease, stroke, diabetes, dementia, congestive heart failure, acne, low or high blood pressure, or obesity. There is also almost no indication of cancer.
The Kitavans have abundant food supply and are not threatened by malnutrition or famine.
> Are you arguing that there were no societies that had caloric surplus up until late in the XX century?
No, only that a caloric surplus is necessary to gain weight. Matter cannot be created from nothing, a surplus of energy is required to perform all the bodily functions and to also build body mass.
A people can have an abundance of food and still not get obese, if they simply don't eat too much of it, relative to their caloric expenditure.
Do we know that? I thought there was some research indicating the hunter-gatherer societies actually had to devote rather little (comparative) time to gathering sustenance.[1]
Is there some research I should be aware of that refutes this, or at least asserts more information as to a likelihood one way or the other?
Your assumption about the laws of thermodynamics predicates that the "Energy out" part of the equation is not somehow effected by the type of "Energy in" (Adding wet sticks to a fire will not produce as much released energy as adding dry sticks or gasoline soaked sticks)
The general argument about carbs or any food with high glycemic response is that these foods are like adding "wet sticks" to the fire. There's considerable science and anicdote to support this.
If you're interested (And not simply not throwing around pithy sound bytes about physics) check out:
Why we get fat (And what to do about it) By Gary Taubes (http://garytaubes.com/)
For some very compelling anicdotal evidence (That also supports some concepts of Paleo) check out http://www.reddit.com/r/keto
Your metaphor of adding wet sticks to a fire is flawed, from a thermodynamics argument. Assuming that the fire is large enough, it will dry out the wet sticks through evaporation/boiling, and the wood's total contribution to the heat ("energy out") will be unchanged.
Now, of course for the people sitting around the fire, some of the heat that would be warming them up or used for cooking is instead used to force a phase change in the water, so it won't be as much "useful" heat, but that meaning of utility - which I believe is the one you want - is outside of thermodynamics.
For what it's worth, "for some very compelling anecdotal evidence" of the thermodynamic approach, see The Hacker's Diet at http://www.fourmilab.ch/hackdiet/ , which uses the "Rubber Bag" model. Unlike the garytaubes.com web site, the entire book and supporting materials are available for free download. The basic premise is the thermodynamic "if you eat more calories than you burn, you gain weight; if you eat fewer calories than you burn, you lose weight." (See also 'Food and fact' where "The rubber bag view of the body and considering only the calorie content of food is obviously oversimplified." and some of the complications are mentioned.)
I believe you are making a different argument, which is that you can't always measure the caloric impact of foods. Under the Hacker Diet, that makes little difference. It uses a feedback system based on weight trends rather than specific calorie counting. There's no need to know that oak combustion produces about 15MJ/kg and boiling water from room temperature takes about 3MJ/kg, because it only looks at 'is there enough heat'?
Thanks for the links on the Hacker diet, the rubber bag concept sounds interesting, I'll check it out.
As for my metaphor - actually I think it holds very true to what you're saying. You pre-qualified that the fire be hot enough to overcome the dampness of the sticks. That's my exact point. Think of the water as insulin and the stick itself as the fat you want to burn. If you're consistently slamming yourself into insulin shock then you'll never burn fat, and you'll end up looking like most of America(Myself included).
It takes very little insulin response to put our fire out.
No one is refuting thermodynamics here - simply stating that making the assumption that the body is a perfect machine (Or set at some guaranteed rate of efficiency) is a flawed outlook.
Taubes makes a great case for this in his examination of Native American Women and their children.
Now you're using the body's metabolism to explain the metaphor to explain the body's metabolism. I don't think it's supposed to work that way. :) To highlight some of the difficulties:
So, insulin shock is the specific heat of water and/or the heat of evaporation? Does fire "slam into" the water?
As a technical point, there's a distinction between heat and temperature. The fire does not need to be "hot", it just needs to have enough heat to evaporate some of the water on the new wood, and of course hot enough to catch the wood on fire. At that point the reaction becomes self-sustaining.
I don't know how to apply that heat/temperature distinction to the metaphor.
If the "fire is out" then what are we using to survive?
(These are rhetorical. I think I know the point you're trying to get across.)
Also, what does a "perfect machine" have to do with anything? Surely not from a thermodynamics viewpoints. I can't think of anyone who thinks of the human body as a perfect machine, and I have a hard time thinking of what that would even mean.
While I'm amused (Really I am, no sarcasm!) with the extension of the fire concept - I think you're just pulling at semantics of my metaphor =)
You make a valid point - lets pull heat and temperature out of it. I'll take the whole metaphor out. If I were to waterdown the through process of ketogenic diets (which are what I'm talking about and share some things with Paleo) I would explain them as such:
Insulin prevents your body from breaking down it's natural stores of energy. When you eat anything with a high glycemic index (Which is most food in the American diet) you have an insulin reaction. While having an insulin reaction, you don't burn fat stores. If you can't burn your fat stores, you don't lose weight. If you can't burn your fat stores and you run out of immediately available energy your bodies 'fire' dims (You crash after that sugar rush)
Ketogenic diets are the only diets that make sense to me, because they so easily explain the different states of weight gain/loss and energy level. I'm interested in hearing other methods of weight management.. but I really feel the ketogenic concept explains the body best.
> Sugar does not cause hyperactivity in children. Double-blind trials have shown no difference in behavior between children given sugar-full or sugar-free diets, even in studies specifically looking at children with attention-deficit/hyperactivity disorder or those considered sensitive to sugar.
> At least 12 double blind randomised controlled trials have examined how children react to diets containing different levels of sugar.2 None of these studies, not even studies looking specifically at children with attention-deficit/hyperactivity disorder, could detect any differences in behaviour between the children who had sugar and those who did not.3 This includes sugar from sweets, chocolate, and natural sources. Even in studies of those who were considered “sensitive” to sugar, children did not behave differently after eating sugar full or sugar-free diets.3
> Scientists have even studied how parents react to the sugar myth. When parents think their children have been given a drink containing sugar (even if it is really sugar-free), they rate their children’s behaviour as more hyperactive...
If a hypothesis depends on a mechanism we haven't observed, then I don't think it's likely to be real.
I've seen some work contradicting him, but would be interested in seeing something refuting him.
Your phrase "Compelling anecdotal evidence is an oxymoron" seems strange. If 5 people told me they saw my wallet outside, I'd be compelled to check, by anecdote, if I'd dropped it on my way in.
If the body digested everything with 100% efficiency and didn't produce waste, and also treated all 'calories' equally, then I'd agree that thermodynamics tells us everything we need to know.
But even people coming from the complete opposite end of the argument to the paleo crowd ("Eat more whole grains!") agree that the amount of heat produced by a substance when it's burnt in a calorimeter doesn't tell the full story about its potential for causing obesity.
I have no idea how cavemen lived, and it doesn't interest me all that much either, but my guess is that they weren't as sedentary and they weren't as proficient in the art of preserving food. Overall, it should have been quite difficult for most of them to create a caloric surplus, day after day.
What I do know is that bodymass is lost and gained with deficits and surpluses of calories.
Transient spikes in insulin and stuff like that are irrelevant. This is well established in nutritional science.
There's quite a lot of research with gut bacteria now and the association with obesity. It's not as simple as caloric intake, it is also the balance of the gut bacteria.
The Venus of Willendorf Is widely regarded to represent an exceptional, ideal image not a typical person. People who are short of food idealise a food surplus.
> The nickname, urging a comparison to the classical image of "Venus," is now controversial. According to Christopher Witcombe, "the ironic identification of these figurines as 'Venus' pleasantly satisfied certain assumptions at the time about the primitive, about women, and about taste." Catherine McCoid and LeRoy McDermott hypothesize that the figurines may have been created as self-portraits.
But let's face it, the evidence must be scant either way.
Still, if people from traditional societies enter the western world they tend to be afflicted even worse from civilization diseases (obesity, diabetes, strokes, heart attacks...). I think part of the problem is that our foods are engineered to trick the regulation of our food intake. Jared Diamond describes how New Guineans empty whole bottles of salt on their food, because they are much more "optimized" for craving salt.
So the energy in/energy out thing might hold, but it is just part of the problem. The real problem is how to regulate food intake appropriately.
Actually Dimaond also describes traditional people overeating to the extreme when they have meat on rare occasions (some kind of meat festival). So of course abundance of food is part of the problem - if those people had meat all the time, perhaps they would overeat immediately. But so we could still learn about sane frequencies of food intake from traditional societies.
If you spend your day harvesting a field or running after animals to pray them, you're not going to be obese, you're more likely to gather fat if your day is taping on a computer, but this has nothing to do with diet.
Also, I won't the lifestyle of a period of our history, as a species, where the expected longevity was something like 30 years against 80+ of today.
Pedantically speaking, a paleo-something probably shouldn't have an axe to grind.
(I don't really have a point, but it's interesting how focused pop culture is on chipping rocks when polishing them is one of the foundational aspects of civilization)
I'm not a "Paleo" person, but the hinting in this article that folks trying to infer better living patterns from the past are loons is faintly preposterous. We have just mounds of evidence (which doubters are free to research themselves) that many pre-Agricultural societies had (and have, actually) far lower rates of the so-called "diseases of civilizations". More abstractly, evolution isn't magic. There is some rate of lifestyle change due to technology that will outstrip evolution's ability to accommodate it.
Hunters and gatherers weren't obese. We are. By irrefutable inference, some lifestyle difference explains this. One valid way to approach the problem of our accelerating obesity is to study what has changed. The theory that I consider most likely at this point is the one argued by Stephan Guyenet, a PH.D. neurobiology researcher who studies the link between obesity and the brain. He posits that modern industrial food is hyperpalatable, so we eat too much of it.
http://wholehealthsource.blogspot.com/2011/10/case-for-food-...
It wouldn't be the favorite theory in the Paleo community, I imagine, but it springs from the same intuition.