NuSI Again: A Bar Too High, Occam's Razor and Rabbit Holes
I weighed in with some initial thoughts on Gary Taubes and Peter Attia's new venture NuSI here. Yeah, I'm going all wet blanket on this deal, but for good reasons grounded in reality in my opinion. I'll leave it to all the others to get all excited about this venture and all the "real science" we'll see come from it. As Gary says of NuSI:
Its purpose is to facilitate and fund rigorous, well-controlled experiments targeted at resolving unambiguously many of the outstanding nutrition controversies — to answer the question definitively of what constitutes a healthy diet.
A bar too high?
What would constitute a rigorous, well-controlled experiment? Well, as I pointed out in my last post, the biggest "knocks" the NuSI gang make on existing research are not really with experimental design per se, but rather with practical limitations in doing human clinical trials. These are:
- The inherent lack of compliance control in free-living studies.
- The monetary and logistics obstacles inherent in metabolic ward studies resulting in studies that of necessity involve smaller sample sizes and/or shorter durations than might be desired.
So ... are we to presume that NuSI will not be funding any free-living studies? One would presume so, since they cannot claim existing science is inferior/inadequate because of lack of compliance control and then go out and fund similar studies. The bar is set even higher on point 2, because the metabolic ward study suffers from a problem other than cost -- finding subjects willing and able to spend lengthy periods of time as subjects in such a setting. However even presuming that obstacle can be overcome, we're back pretty much to a cost issue that is the basis for why most metabolic ward studies are small and short in duration. NuSI has set the bar VERY high in terms of expectations. The "real science", as Fat Head calls it, had better be large, long metabolic ward studies ... or else NuSI itself would dismiss it as inadequate to answer the burning questions.
Let's look at NuSI's other problems with existing science. Points 3&4 are really the same side of the coin that Taubes discussed in Calories, fat or carbohydrates? Why diets work (when they do).
3. Caloric restriction of the control diet, and so effectively carbohydrate-restriction of all the competing dietary interventions;
4. Caloric restriction of the carbohydrate-restricted diet, thus building into the experiment the assumption to be tested – that the carbohydrate content of the diet can influence weight loss independent of total caloric content.
That post focused on the Shai et.al. study basically making the point that Shai and her colleagues were just too mired in old paradigms about calories to properly design their study. This study is among the "bad" free-living studies. I say that studies like Shai (and others like Gardner, Foster, Dansinger, etc.) measure up differently on the "science" scale for various reasons. Mostly these studies fall short because there is not sufficient monitoring and reporting compliance and those shortcomings are compounded catastrophically by intent-to-treat analyses and variations thereof. There was one study a few years ago where they actually reported and compared predicted weight losses for subjects who dropped out. Anyone recall the study I'm referring to? Seriously, if we're talking about trying to reverse obesity in the most healthy and sustainable fashion, the major drawback of all of these studies is that we have no clue regarding compliance, and those that don't comply and even dropouts are often included in the numbers. This tells us nothing, and I think the intent-to-treat analysis is what is wrong in many cases, not the "science".
But back to Shai for a moment, because people should be reminded of what a big deal Gary Taubes makes over this "bad science" to try to support his alternate hypothesis! It's why I "called him a sheister", only I didn't really, it was a play on words with Shai's name in: Gary Taube$, Shai-ster. Taubes repeated the lecture analysis in one of his book press releases (aka blog posts), Taubes: Calories, fat or carbohydrates? Why diets work (when they do). It really does make one wonder how NuSI intends to identify well designed studies to fund when one of its co-founders flat out says that dietary intake reports such as those in Shai should be taken with a grain of salt, and then launches into a serious analysis of the data nonetheless. I wrote my own follow-up post about this debacle, CarbSane: Calories, fat or carbohydrates? Why diets work (when they do).
There have been a number of studies where macronutrient ratios have been altered rather considerably in isocaloric contexts. One such study was a small metabolic ward study in obese women, Grey & Kipnis. NuSI includes this study in their review of the literature but complains that the low carb diet of the weight maintenance phase was too high at 25% carb. I'm going to get back to that in a moment, but I addressed G&K in my Why diets work post just linked to.
Protocol 1 - Effect of Carbohydrate Content in Caloric Balance: Subjects ate ad libitum for 2 weeks to establish weight maintenance calorie needs, then fed at that caloric level for 3 weeks on a LC diet (C/F/P = 25/53/22), and switched to a HC diet (C/F/P = 62/18/20) for the final 3 weeks.
Now G&K suffers from the problems of metabolic ward studies. It was small (7 subjects in this leg) and each diet was only for 3 weeks, but the difference in carbs was substantial! Yet 5 of the subjects weights stayed rock steady level throughout, while one gained a little, one lost a little. The rollercoaster curves are for fasting insulin which, as you can see, is all over the place. Taubes & Attia look at this study and it's that carb consumption is not restricted enough to see an effect in three weeks. But they apparently ignored the second leg of the study. Again, admittedly very small (only 3 subjects) but here's their protocol:
Protocol 2 - Effect of Carbohydrate Content in 1500 cal CRD: Here the subjects again established baseline for 2 weeks and were then cycled between 1500 cal formula diets: 4 weeks HC (C/F/P = 72/1/27), 4 weeks LC (C/F/P = 0/74/26) and finishing up with 4 more weeks HC.
They all lost weight, pretty steadily, when calories were cut. And they kept protein roughly constant and switched them between a no-fat to no-carb back to no-fat diet for 4 weeks each.
It's obvious to everyone but the most blinded TWICHOOB that it is calories and not carbohydrates (or insulin) that determine body weight.
The Occam's Razor in all of this is that based on every means and measure, on every graph, one thing is clear: Americans consume more calories now than we did before the obesity epidemic. The caloric amount varies -- I've seen ~300 cal/day quite frequently, and as high as 600 cal/day. You can't get away from this fact, and yet they will contort the macro intakes using percentages and spin things to blame carbohydrates. But there's no denying that we are overconsuming, and the other edge of this razor is this: Our carbohydrate consumption has not changed that considerably. Yoni Freedhoff at Weighty Matters summarized my point better:
What she's saying is that from a macronutrient percentage perspective, the difference between the 1970s consumption of a diet containing 45% carbs (for women) and the 2000s diet of 52% (and for men the difference between 42% and 49%) is pretty insignificant and that 1970 diets were anything but low-carb and yet our weights were so much better.Because part of G&K ran afoul of NuSI's point 5 against existing science:
5. Testing diets of only marginally different nutrient content — “low carbohydrate” diets, for instance, that are still 30% or more carbohydrate.
They lower that bar to 25% to dismiss G&K, but the weight maintaining diets in that study varied carb content between 25% and 62% -- that is pretty darned significant, especially when folks are trying to blame a 7% increase in carb proportion of the American diet for the obesity epidemic. Let me repeat that in a slightly different fashion:
Conventional Wisdom: The obesity epidemic was caused by increased consumption of food (calories)
TWICHOOBS: The obesity epidemic was caused by an increase in the proportion of carbohydrate calories of 7%.
Put this way, TWICHOO seems ever the more ridiculous. Even if we turn our eye on the types of carbohydrates, it's a tough point to sell because flour and sugar have been around far far longer than this obesity problem.
A relative new-comer on the LC/paleo scene is Abel James. One of his favorite sayings when trashing folks who look at the science, is to belittle them for chasing down rabbit holes. Part of that goes to the very core of doing the studies or analyzing the results of studies that have little or no practical application or relevance. And yet, as I've just discussed vis a vis their point 5, NuSI seems to want to do just that. Even if, in a metabolic ward context, NuSI funded scientists operating with optimal intelligence could demonstrate that humans get fatter on a 50% carb diet vs. a 5% carb diet ... would this answer the burning question of what caused the obesity epidemic? No. Because there was no such existing carbohydrate restriction, nor was there any such massive increase. Thus it is a rabbit hole like any other. Indeed it would appear that NuSI's last two problems with current nutrition science relate to scientists not going down those rabbit holes. iction to determine the cause of this obesity epidemic. Nevermind that we NEVER ate anything close to low carb before this whole mess. NuSI bemoans testing diets that are "only marginally different nutrient content" when we have this obesity epidemic resulting from changes in the nutrient content of the American diet that are so nominally different, they're not even worth studying! Better to go down the "good science" rabbit hole testing extreme low carb diets that weren't consumed before this epidemic.
It would appear that when judging the merit of nutritional science, Taubes and others of like mind, dismiss any research not designed to answer their questions. Like there's no other question to be asked or answered, and it's those questions that are viewed as rabbit holes. Their last points of contention with the bad nutritional science out there:
6. Manipulation of fat and protein content in the diet, rather than the carbohydrate content itself.
7. The use of habitually lean subjects to test the effect of nutrient composition on the accumulation of excess fat.
Point 6 seems aimed at that Bray overfeeding study where they kept carbs constant as a percent. I discussed that study in The First Law of Thermo still doesn't violate The Second Law. That study did address the relevant question of whether protein can be "fattening". The verdict? Not really, the caloric surplus led to relatively equivalent increases in fat mass irrespective of protein content. But this study may illustrate a role for protein in the obesity epidemic, as assessed by BMI. The low protein group ate rather low protein (6%) while the moderate protein group was average American consumption (15% though in many studies normal content tends to run a few percentage points more, though not the 26% of the high protein group). There can be no argument that Americans are overeating, but we're overeating with a protein level that promotes weight gain -- *weight* that is not distinguished between fat and lean mass. In the Bray study, the fat mass gains were roughly equivalent while the lean mass changes were quite telling. The low protein group actually lost about 1.5 lbs of lean mass while the medium and high protein groups put on roughly 6.3 and 7 lbs of lean mass respectively. It's fair to say that "sufficient" protein favors weight gain in an overfeeding context, but higher protein does not complicate this much. It certainly doesn't protect against fat gains or weight gain. I have some further thoughts on this to share another day.
As to point 7, this is true to a point, but for there to be an obesity epidemic in the first place, a goodly portion of habitually lean humans in the 70's somehow became susceptible to obesogenic foods. A goodly number of habitually lean humans began overeating and getting fatter and fatter as a result. The foods were there ... McD's ... cakes ... white bread ... TV dinners ... Kraft Mac & Cheese ... Coke ... breakfast cereals (oh and the kids ones had more sugar and were touted to having it!) ... This epidemic simply cannot be blamed on single digit differences in carbohydrate consumption well, WELL, above the level it would even be relevant. Rabbit hole.
I can hear it already. Tearing down. No value. Unsupportive of big ideas. Well, next up ...
I can hear it already. Tearing down. No value. Unsupportive of big ideas. Well, next up ...
Just Do It
And is it written somewhere that only metabolic ward studies are funded? If you want to study the influence of health advice, it should be sufficient to ask the subjects to follow certain rules. Also after the study, all you can do is just advice people to follow certain rules. I do hope no one wants to lock all overweight people up in a metabolic ward.
You could study the influence of food quality outside of a ward. Just give the people ecological or normal meats and see what is the difference. I guess they will eat it and not throw it away and buy meat themselves.
You could do something similar with fresh produce and foods which have been harvested a few days earlier. Or with no-fat dairy, normal dairy and raw dairy.
You could study the influence of intermittent fasting, by locking up the subjects one day a week, if you do not trust them. If you turn this day into a relaxing sauna day at a beautiful spa, the volunteers may participate for free.
Americans at the beginning of the 21st century are consuming more food and
several hundred more calories per person per day than did their counterparts
in the late 1950s (when per capita calorie consumption was at the lowest level in the last century), or even in the 1970s. The aggregate food supply in 2000 provided 3,800 calories per person per day, 500 calories above the 1970 level and 800 calories above the record low in 1957 and 1958.
Of that 3,800 calories, USDA’s Economic Research Service (ERS) estimates that
roughly 1,100 calories were lost to spoilage, plate waste, and cooking and
other losses, putting dietary intake of calories in 2000 at just under 2,700 calories per person per day. ERS data suggest that average daily calorie intake increased by 24.5 percent, or about 530 calories, between 1970 and 2000. Of that 24.5-percent increase, grains (mainly refined
grain products) contributed 9.5 percentage points; added fats and oils,
9.0 percentage points; added sugars, 4.7 percentage points; fruits and vegetables together, 1.5 percentage points; meats and nuts together, 1 percentage point; and dairy products and eggs together, -1.5 percentage point.
Some of the observed increase in caloric intake may be associated with the increase in eating out. Data from USDA’s food intake surveys show that the foodaway-from-home sector provided 32 percent of total food energy consumption in 1994-96, up from 18 percent in 1977-78. The data also suggest that, when eating out, people either eat more or eat higher calorie foods—or both—and that this tendency appears to be increasing.
Although multiple factors can account for weight gain, the basic cause is an excess of energy intake over energy expenditure. In general, Americans’ activity levels have not kept pace with their increase in calorie consumption. Many people apparently are oblivious to the number of calories they consume.
CICO - eat LESS - Calories DO COUNT
The studies will be defined as well designed because NuSI is funding them.
I have a feeling they will be changing their story on free living and/or metabolic ward studies, depending on which they choose to fund. The metabolic ward study will be "just long enough," or the free living study will have "great compliance." Whether or not it is actually true, they will find some way to spin it so it looks good.
"You make choices in the food you want to purchase, and if you make the wrong choices relentlessly and perpetually, you're going to have health consequences," said John Doyle, co-founder of the Center for Consumer Freedom, a coalition of restaurant operators and individuals. "But that is not something that the restaurants are responsible for."
Fortunately the lawsuit got thrown out
"Where should the line be drawn between an individual's own responsibility to take care of herself and society's responsibility to ensure others shield her? The complaint fails to allege the McDonald's products consumed by the plaintiffs were dangerous in any way other than that which was open and obvious to a reasonable consumer," Sweet said in his ruling."
People eat too much and exercise too little - When you go on a LC diet you generally cut out the processed crap and reduce your calories
The only question is why do a lot of people - like Jimmy Moore - REGAIN most of the weight they lose?
Methinks they are underestimating the calories - after all - fat has 9 calories per gram so if you go on VLCHF diet - say 80-85% fat - perhaps you are simply eating too much - after all those tablespoons of coconut oil and sticks of butter do add up
Gotta laugh at that.
I am NOT advocating for the Food Pyramid, but if every American stuck to the FP rigorously - big guys at the larger portion end, smaller ladies at the lesser portion end - we wouldn't have this obesity epidemic.
C'mon, Jimmy didn't get fat eating 11 portions of carbs a day. He ate 11 portions X 4, plus loads of fats - and protein. He had to be eating upwards of 4000 cals a day when he weighed 410 pounds.
There's a lotta calories in one pecan log!!
Does the USDA fact book :-) provide any arguments why the main reason must be that people do not count calories accurately enough? Going by the above numbers, if all they have is correlation, they could just as well blame grains, added fasts, oils or sugar.
I think two things need to happen before we make any progress though. 1) Researchers need to come to a consensus as to what makes foods obesogenic vs. satiating. Clearly such a concept exists because of the ability for most of human civilization to remain lean without counting calories. And 2) we must acknowledge that obesity is largely not a behavioral disorder and that we can't blame people who have chronic hunger for over-consuming.
"What does the data show? Between 1970 and 1980, calorie intake is relatively stable, rising only 1.2 percent. Between 1980 and 1990 consumption jumped 9.6 percent. Then, from 1990 to 2008, the last year with data available, the number of calories rises another 11.4 percent for a grand a total of 2,673 calories available per person–23.3 percent more than consumed in 1970."
"By analysing a range of data, the researchers predicted how much weight they would expect Americans to have gained over the 30-year period studied if food intake was the only influence and compared that to actual weight gain over that time.
The researchers found that in children, the predicted and actual weight increase matched exactly, indicating that the increases in energy intake alone over the 30-years studied could explain the weight increase.
“For children, the predicted weight gain of 4.0 kg matched the actual weight gain, and for adults, the predicted weight gain of 10.8 kg was a little more than the actual gain of 8.6 kg,” Professor Swinburn said.
“To return to the average weights of the 1970s, we would need to reverse the increased food intake of about 350 calories a day for children (about one can of soft drink and a small portion of French fries) and almost 500 calories a day for adults (about one large hamburger)."
"The scientists started by testing 1,399 adults and 963 children to determine how many calories their bodies burn in total under free-living conditions. The test is the most accurate measure of total calorie burning in real-life situations.
Once they had determined each person's calorie burning rate, Swinburn and his colleagues were able to calculate how much adults needed to eat in order to maintain a stable weight and how much children needed to eat in order to maintain a normal growth curve.
They then worked out how much Americans were actually eating, using national food supply data (the amount of food produced and imported, minus the amount exported, thrown away and used for animals or other non-human uses) from the 1970s and the early 2000s.
The researchers used their findings to predict how much weight they would expect Americans to have gained over the 30-year period studied if food intake were the only influence. They used data from a nationally representative survey (NHANES) that recorded the weight of Americans in the 1970s and early 2000s to determine the actual weight gain over that period.
"If the actual weight increase was the same as what we predicted, that meant that food intake was virtually entirely responsible. If it wasn't, that meant changes in physical activity also played a role," Swinburn said. "If the actual weight gain was higher than predicted, that would suggest that a decrease in physical activity played a role."
The researchers found that in children, the predicted and actual weight increase matched exactly, indicating that the increases in energy intake alone over the 30 years studied could explain the weight increase.
"For adults, we predicted that they would be 10.8 kg heavier, but in fact they were 8.6 kg heavier. That suggests that excess food intake still explains the weight gain, but that there may have been increases in physical activity over the 30 years that have blunted what would otherwise have been a higher weight gain," Swinburn said."
If eating processed foods causes people to over-consume (as you imply by saying cutting them will lead to calorie reduction), then why is the common diet advice, "a calorie is a calorie and the solution is eat less and move more?" This implies it is okay to eat processed junk foods because humans have the mental capacity to effectively moderate them, but clearly we don't based on the statistics!
There are gluttons who don't care, but it is difficult to imagine that people just lost the sense of "personal responsibility".
A big flaw in using NHANEs data to quantify macronutrients is the amount of fats wasted in fast food preparation. Most of the fat in a fryer actually goes down the drain. Same with drippings from roast meat or chicken. As this wastage is of the most calorie dense food, the actual ratios consumed could be quite different. Our ancestors were not nearly as wasteful of fats in their cooking, before the invention of the deep fryer.
If consumers are satisfied with a small portion of your product, your company is going to wind up in bankruptcy court. You have to come up with something that is impossible to stop eating.
Since when grilling on a flame less wasteful of fats than deep fat frying?C'mon, you can do better than that!
Deep frying is more wasteful than grilling because fats are discarded which were never in the food to begin with. Grilling a steak, you can only waste the fat that came with it. Normal frying, you only waste a thin layer of grease. But deep frying yields enough waste oil for people to run their cars on - oil that was extra to the process. Like the water you boil your spuds in, compared to the water in the spuds to begin with; most of it goes down the drain.
If the increase in fa(s)t food culture means more deep frying, as I think it does, then data on fats produced or sold are actually consumed.
Cooking habits matter when tracking consumption.
Past generations saved waste fats from one meal to use in the next.
"data on fats produced or sold are increasingly overestimating the amount consumed."
I spent 2 high school summers working in a donut shop kitchen.
They never threw away any oil regularly, just for cleanup when the heating elements were clearly fouled.
What has Taubes succeeded in doing? Nothing, just yet, other than building an organization he's apparently received funding for. Ultimately having his name attached to this initiative undermines it. Though I will wish him success in proving his fairy tales wrong.
I see your point about the frying now -- wasteful of total fat, not fat in the food. So since that is mostly veggie oil now, the increase in veggie oil consumption -- even adjusted for waste -- may be overstated. Good point.
a different one per summer, once at a (not yet national) chain
and another at a family owned place
he won the lottery.
in past sociology research "success" and "lottery winner" don't generally go together; one of the few things some of the self help movement occasionally gets right (then put their feet in their mouths and THEN shoot themselves in the foot with games like "imagine you won the lottery ...)
Taubes managed to dig out and dust off the old idea to deal with obesity and convinced others to give it another try after last 50 years of fearing all fats and considering vegetarianism the ultimate healthy choice. He managed to make others to listen, which is a separate skill.He didn't need to offer a new theory because it already existed but was forgotten/demonized/disproved .What he is doing now belongs to the category of marketing, not science.I hope his efforts will make LC diets more accepted in society and in medical applications. There is no way all people will stop eating grains because of LC diets getting more popular. I hope in a future if I go to a hospital to have a choice which includes a LC or a ketogenic diet.
As I understand, drug trails are done in order to give a "green light" for use of the drug in a general population. I want a "green light" for ketosis and LC diets(not the same), I want to see clinics in a future for people who need a supportive environment for fasting before chemotherapy, a ketogenic diet recommended for sufferers of heart attacks or strokes, for people with incurable brain cancer and Parkinson, and much more.
Galina, in 2009 I hoped to find solid science to discuss with my doctor about how I was eating at the time. What I found was garbage, and Taubes' theories will hopefully not harm the effort to have LC evaluated for longterm healthfulness. I'm not optimistic.
As to your last paragraph, I'd like to see most of that too. NuSI the answer? Excuse me while I laugh and cry at the same time. The best thing that might come of this is that publicity will show that Arnold foundation is interested in such things and a doctor looking into such things contacts the foundation directly for funding.
I am not for mass application of ketogenic diets, but for an acknowledgement of potential benefits. For example, I don't advise my son to eat meat alone, but when he feels like he may be getting flue, he really cuts on carbs consumption. Atkins promoted his diet mostly for a weight loss, but I see it has more potential for therapeutic applications, and I want the bad reputation (which is partially the Atkins legacy due to his gift to alienate opponents)to disappear. I recently found out that the nurse in ob/gyn place who usually sees me during my annual appointment started to recommend to try a LC diet to ladies with bothersome menopausal symptoms.
It well could be a temporarily application. A paleo-crowd (Richard Nikoley is a good example,and Dr. Kurt Harris) demonstrated that safe starches could be successfully reintroduced back in many (maybe most)cases.
Post a Comment
Comment Moderation is ON ... I will NOT be routinely reviewing or publishing comments at this time..