Math Vs. The New Low Carb Is Better Study
Another study that shows one way of dieting is better than another suffers from the same problems as all of them.
Low Carb Is Better (Again)
Low carb fans currently freak out over this study, that shows how superior their lifestyle is for reducing weight compared to a low fat diet.
Really? Or will this be another exercise in counting your carbs before not trimming the fat off the sirloin steak?
The latter, because a trivial calculation makes the low carb superiority disappear into a cloud of saturated bad math sizzle.
Caloric Math For Beginners
To get my drift on this read the full study or, if you don’t have access to Annals, head over to MedPage Today, whose author cites the relevant numbers.
Got it? Ok. The self-reported daily calories showed the low fat group on average ate 79 kcal more per day. 79 x 365 = 28,835 kcal. Losing 1 lb of weight requires a deficit of ~3,500 kcal, which means 28,835 / 3,500 = ~ 8 lbs or 3.6 kg. According to the study, the low carb group lost 5.3 kg, the low fat group 1.8 kg.
What do you get when you add 3.6 + 1.8? 5.4 kg.
28,835 Calories? Ah, Those Aren’t Significant!
I asked Dr. Lydia Bazzano, the study’s lead author, about the discrepancy in calories between the low carb and fat groups. She replied:
The differences are not statistically significant except at 3 months so it’s not possible to say that these differences are not due to random chance variation at 6 and 12 months. So no, in my opinion it does not explain the difference. But a better question is why would there be a difference at 3 months? Fat and protein provide a feeling of satiety or fullness and perhaps that led them to eat less? Another issue is the loss of more fat as a proportion of the weight lost in each group in the LC group. Calories in/calories out doesnt explain that.
Yeah, the difference may not have been significant most of the time, but a total difference of 28,835 kcal is.
Unless, of course, you follow Dr. Bazzano’s line of reasoning that a calorie is not a calorie. It’s a mindset low carb aficionados readily embrace, but I’m surprised that a qualified scientist resorts to it for an explanation.
Going With The Times
In my opinion it was a badly set up trial that provided the low carb superiority and not any inherent advantage of eating low carb.
But when I read about this in the New York Times their author couldn’t hide how amazed he was:
[…] More recent clinical studies in which individuals and their diets were assessed over time have produced a more complex picture. Some have provided strong evidence that people can sharply reduce their heart disease risk by eating fewer carbohydrates and more dietary fat, with the exception of trans fats. The new findings suggest that this strategy more effectively reduces body fat and also lowers overall weight.
This makes me grind my teeth. Before publishing statements this strong, one would think that a New York Times reporter closely scrutinizes the study he writes about. The math doesn’t require a science degree and if I was able to inquire with Dr. Bazzano, a New York Times reporter noticing this discrepancy should be too.
Calories In Vs. Out
I wonder what he’d have made of her reply. The man wrote a diet book himself, where he tells his readers that losing weight boils down to calories in vs. out.
Who’d have thought?
Picture courtesy of Steve Snodgrass.
30 Comments
Low-carb v.s. low-fat is not where the truth lies. It’s the omega-6 linoleic acid content of the food supply that is causing much of the confusion. Excerpts from a 2013 Joseph Hibbeln interview:
“Just as all polyunsaturates are not created equal, all high fat diets are not created equal. A good example of this is an animal study we did where we compared three high fat diets. All with 60% of calories from fat, in mice. We compared high fat diets that resembled the linoleic acid, Omega 6 intakes, comparable to the levels at the beginning of the century, which was about 1 percent of calories, and those high fat diets with 8 percent of calories, more similar to the amount of Omega 6 in the diet simply from soy oil in the U-S diet, today. Moving from 1% to 8% linoleic acid in the mouse diets, not only tripled the levels of arachidonic acids, but also tripled the levels of a critical derivative of arachidonic acids, which is an endogenous cannabinoid, which creates a similar affect to marijuana. So it’s the brains own marijuana like molecules, and we were able to triple the body’s marijuana like hormones, three times higher in the liver and about 20% higher in the brains just by altering the linoleic acid in those two high-fat diets. Normally those high fat diets used for mice in studies are composed of high linoleic acid, found in soybean oil. When we deleted that one single molecule, the Omega 6 fatty acid, we were able to obliterate the ability of a 60% high fat diet to induce obesity in the mice…And we did it also in diets that were 35% of calories from fat, and also diets that were 12% of calories from fat. We were able to induce obesity in low fat diets, in the mice, by changing the bioactive properties of the fat, not just that it was high fat and more calories.” http://www.meandmydiabetes.com/2013/03/10/vegetable-oil-associated-with-more-heart-deaths-nih-scientist-joe-hibbeln/
Here’s one of the research papers Dr. Hibbeln referred to in the above excerpts: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3889814/
In my opinion, this is breakthrough research and potentially the best explanation for the current global obesity epidemic.
That’s interesting, but I’m not certain what the implications are.
You’ve missed the point. This wasn’t a calorie controlled study. It was a free living study that counseled fat reduction vs carb reduction WITHOUT counseling calorie reduction.
If the low carb group ate less calories, then they did so out of a reduction in hunger. A statistically significant reduction in calories, given the study design, would bolster the case for low carb as a practical diet paradigm substantially.
Then this study was looking at something different than postulated.
Ah….no. The difference in calories doesn’t explain why one diet was better than the other since the very idea that food calorie intake is linearly and directly related to weight is false. Check out the documentary “Why Are Thin People Not Fat?” (it’s up on YouTube) and check out Sam Feltham’s overfeeding experiments.
This post from Gary Taubes should also clarify things: http://garytaubes.com/2010/12/inanity-of-overeating/
Quote:
Now, if you gain 40 pounds of fat over 20 years, that’s an average of two pounds of excess fat accumulation every year. Since a pound of fat is roughly equal to 3500 calories, this means you accumulate roughly 7000 calories worth of fat every year. Divide that 7000 by 365 and you get the number of calories of fat you stored each day and never burned – roughly 19 calories. Let’s round up to 20 calories, so we have a nice round number.
So now the question: if all you have to do to become obese is store 20 extra calories each day on average in your fat tissue — 20 calories that you don’t mobilize and burn — what does overeating have to do with it? And why aren’t we all fat? Twenty calories, after all, is a bite or two of food, a swallow or two of soda or fruit juice or milk or beer. It is an absolutely trivial amount of overeating that the body then chooses, for reasons we’ll have to discuss at some point, not to expend, but to store as fat instead. Does anyone – even Jonah Lehrer or the neuroscientists he consults – think that the brain, perhaps in cohort with the gut, is making decisions about how much we should eat, on how long we stay hungry and when we get full, so that we don’t overshoot by 20 calories a day. That’s matching intake to expenditure with an accuracy of better than 1 percent.
Calories in vs. out has been proven over and over again. There is not one peer-reviewed study proving the opposite.
As for Gary Taubes:
http://wholehealthsource.blogspot.com/2011/08/carbohydrate-hypothesis-of-obesity.html
No it hasn’t. Here’s the study that proves it does not: https://www.youtube.com/watch?v=dAQr77QMJiw
I lost weight eating low fat, something that could never happen if Taubes was right!
No one eats the same amount of food or calories every day, nor burns the same amount every day.
Exactly.
You keep using that word, significant. I do not think it means what you think it means.
We could only answer that if you tell me what you think I think it means and then what you think it means.
I do wager that my definition is correct.
It would appear that someone believes the calorie Vs calorie dogma. Too bad there isn’t a single study that proves consuming 3000 extra calories will result in a pound of fat. It never happens. All we know for sure that is true is how manny calirirs are in a lb of fat. Nutrition isn’t physics (law of thermodynamics), its biological. That doesn’t mean the law of thermodynamics is wrong it just means that it says nothing about how fuel is partitioned in the body (hormonal influence etc).
It only tells us that energy can’t be created only converted to another form. It doesn’t tell us the reality which is that excess calories if consumed in the presence of carbohydrates MAY be stored as fat thanks to high insulin levels (from the carbohydrates) but in the absence of insulin the body manages to just increase the metabolic rate to burn excess energy.
Which is how someone like myself who used to get fat eating 4-5000 calories can now eat that without getting fat…because my insulin is low I can’t physically store the extra calories. I have to burn them or my appetite is suppresed the next day and I don’t eat as much.
“Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.”
http://www.nejm.org/doi/full/10.1056/NEJMoa0804748
There are tons of them. Now show me one where people ate above maintenance and still lost weight.
Not going to argue that a calorie doesn’t count just the dogma that is calorie in vs calorie out. All calories aren’t created equal.
Nobody is saying reduced calories don’t work. Starvation always works in losing weight. What is sustaineable? A diet that reduces calories because it increases satiety (high fat low carb) or a diet that just restricts calories (low fat high carb SAD)? You still won’t find a study that proves calorie in vs out math. If the math worked we could actually predict weight loss and success would be easier.
It never adds up. Animals don’t count calories and yet they can maintain weight and yet somehow poor humans have to count calories. Wrong. You just have to eat food we were designed to eat. I eat all the food I want without counting calories. 6’2 male 255 to 185 using high fat, low carb and moderate protein diet. And you never have to count calories ever again.
Rats fed double as much as the control group gained double as much weight:
http://www.ncbi.nlm.nih.gov/pubmed/8792099
Diets with different fat compositions but similar calories led to similar weight gain:
http://www.nrjournal.com/article/S0271-5317%2808%2900257-1/abstract
And, btw, if you check my about section, you will see I lost 33 lbs on a diet where I did exactly that, count calories. The average loss per week was 2 lbs, just as I had predicted through my calculation.
Rats aren’t people so comparing them to humans isn’t very helpful. We got most of our horrible science about fat from rabbit studies.
Feeding herbivores a high fat diet high calorie diet just tells us that rats and rabbits didn’t evolve to eat fat. The exact opposite is true for humans.
I don’t need a poorly designed study that controls for calories to tell me anything about fat content or composition if carbohydrates aren’t controlled. Again, the presence of insulin requires fat storage. Total calories tell me nothing about fat storage. The amount of insulin in the presence of excess calories is what matters and we all know what macronutient stimulates insulin secretion and thus fat accumulation.
You ask for evidence and decide it’s not good enough. You ask for more evidence and decide that too is not good enough.
Already above I linked you a large study showing that macronutrient composition played no role in weight loss.
If you like to treat low carb as a religion and if it works for you, fine. Whatever rocks your boat. Just don’t go claiming that it has science behind it or is superior to any other form of weight loss. I already above wrote that I lost weight in the exact way you thought impossible.
So where’s your research?
Regarding Bazzanos statements: “Another issue is the loss of more fat as a proportion of the weight lost in each group in the LC group.” Several commenters have casted their methods for assessing body fat loss (bio-impedance) as unvalid.
I’ll quote James Kriger:
“Researchers have looked at the accuracy of BIA for tracking body fat change over time. In one study, the disagreement between BIA and the 4-compartment model ranged from -3.6% to 4.8% for measuring change. This means you could lose 3.6% body fat, but BIA would show no change. Or, BIA could tell you that you lost 8.8% body fat when you really only lost 4%.” (http://weightology.net/weightologyweekly/?page_id=218)
But even if the effect was real, that may be explained by the large difference in protein intake. A higher protein intake has been shown to limit the reduction in thermogenesis that usually happens with calorie restriction. So calories in/out can totally explain it.
I also noted that both groups reduced their waist circumference, with no statistical significant difference.
You are right. However, how can you argue with a religion? 🙂
Just one small sample of the science behind low carb.
http://www.reddit.com/r/keto/comments/2fd1u6/science_low_carb_vs_low_fat_weight_loss_studies
First off though, just pull out your physiology book from college and read up on insulin. Second, pull out your evolutionary biology books and anthropology books and read up on what foods were available to man before grain production was invented.
If neither of those approaches interst you than read the works of Gary Taubes, Dr. Stephen Phinney and Jeff Volek, Nina Teicholz, and Dr.Eric Westman and Dr.Peter Attia’s blog where he explains a lot of the science. Dr. Attia and Gary Taubes created NUSI with $100 million in funding to help sway those who aren’t convinced by the basic science and need more peer reviewed studies than what’s out there now. They are working on some amazingly controlled and scientifically sound research as we speak.
There’s a small sample. I don’t vouch for the studies referenced but if all you care about are studies, you can start with the ones listed in the link provided.
“Design Your Diet
The only diet you most likely will be able to follow through is the one that suits your individual needs.”
We do agree on this.
There is no magic bullet but understanding what actually makes us fat and not what 50 yrs of bad science created dogma tells us makes us fat is THE most important thing in nutrition that must change. It will eventually but that may take a couple more years. Once people (and doctors) reconnect the dots on insulin’s role as the master fat storage hormone and what micronutrients primarily drives it (carbohydrstes), we will start to make progress. Until then, what is intuitive and not scientific fact will remain the status quo. Intuitively, it makes sense that when you do an autopsy and look at the yellow slippery substance that’s everywhere in an overweight or obese person and you dissect their arteries and see a waxing yellow substance coating it’s walls – – intuition tells us what the culprit is – – fat. What we forgot over the past fifty years but knew before then is what caused that excess deposition of fat was not dietary fat.
It wasn’t dietary fat or extra calories that caused it. It was the overconsumption of grains, starches and sugars. Excess calories in the PRESENCE of excess insulin will result in fat deposition. Excess calories without excess insulin has a couple different paths to take. It could cause a decrease in appetite OR an increase in overall metabolism but it’s extremely difficult but not impossible (if you have high cortisol levels instead) to be deposited as fat without excess carbs stimulating insulin secretion.
Fat does not cause insulin spikes and protein only can in excess (gluconeogensis). Thus, what seems intuitive doesn’t make for fact and doesn’t substitute for science. This disconnect in what causes insulin secretion and thus fat deposition is at THE heart (pun intended) of the obesity epidemic that is becoming the scourge of our species.
If the current dogma were true we wouldn’t be moving in the direction we are. We’ve been asked to eat more healthy grains, eat more fruit and veggies and eat less fat. We’ve done all of those things but somehow we just don’t have the willpower to put thefork down and exercise more.
Or we could investigate the alternative hypothesis which is that the proportion of micronutrients we eat causes us to produce more insulin (the primary fat storage hormone) and be more hungry because our body is doing what we’ve asked it do – – drive excess calories into fat cells leaving our bodies with less energy and increased appetites. The body wants to overcome this energy deficit because energy is being physically driven into our fat cells because of our high insulin producing diets and not making its way into our tissues. This blood sugar roller coaster (insulin driving sugar out of our blood) makes us constantly hungry and tired. That isn’t our natural state. It may be considered normal by the current establishment but it doesn’t make it healthy or ideal. Get off the blood sugar/insulin roller coaster. That is still a choice and why it’s not a magic bullet. You have to decide to do it and it’s not easy. Quitting sugar is like quitting smoking.
About Taubes, as already linked above:
http://wholehealthsource.blogspot.com/2011/08/carbohydrate-hypothesis-of-obesity.html
And again: I lost weight in the exact way you said was impossible. And I have kept it steady for six years, still eating carbs.
Replace micronutrients with macronutirents. Dang autocorrect.
I’ve never said it was impossible just that it doesn’t really work for the majority. Some people are sensitive to carbs, some less so (you), and some very much so (myself) and the rest. We actually don’t completely understand why this is the case. We hypothesize that genetics have something to do with it but we don’t fully understand it. Guess who is spending money trying to figure out that exact question? Gary Taubes and Dr. Attia at NUSI. As for that article, I still see a lot of animal experiments. If animals handle nutrients differently than why would insulin response be any different as well. He says a whole lot there but I haven’t looked at all of the sourcing.
Mike, have you actually read the study protocols for the NuSi experiments? If so, you must have notised how they will make the subjects lose weight: by lowering their calorie intake by ~40 % below their energy requirements! The weight loss diet will have “45% carbohydrate, 30% fat, 25% protein; 40% below subjects’ calculated caloric needs for weight stability, minimum 1,200 kcal (“calories”) per day” (In free-living conditions..). How is that going to answer anything?
Which one of the three are you talking about? There’s three studies and if my memory serves me one of the studies is being run by a vegetarian who is hoping to prove Attia and Taubes wrong. Attia and Taubes have brought together a “team of rivals” so to speak. The only requirement being that the studies authors are rigorous in their controls and repeatable. I have an idea of why the study participants calorie intakes would be lower but I’m curious which one you are referring to.
The vegetarian (vegan?) you are referring to is Christopher Gardner. He’s doing the diet x genotype study to see “if there is a genetic predisposition to being more successful in weight loss on a Low Fat vs. a Low Carb diet.”
I refered specifically to Boston Children’s Hospital Study. It’s primary endpoint is actually energy expenditure, not weight loss. The same goes for the third study, by Kevin Hall et al.
Someone cited “Why Are Thin People Not Fat” LOLOLOLOLOLOLOLOLOLOLOLOLOLOL