Still More Calories ... And a rant :-)

Probably the most annoying calorie discussion I'd come across recently has to be Stefani Ruper's discussion about this article in Science Magazine, Have We Been Miscounting Calories?, entitled They’re Still Doing It Wrong: Have We Been Miscounting Calories?  Read the article first and then Stefani's take.  I sort of wish I had to know if her take came off as badly in that order, but you can't undo.  

From the article:

In a wide-ranging discussion of how food is digested in everything from humans to rats to pythons, the panel reviewed a new spate of studies showing that foods are processed differently as they move from our gullet to our guts and beyond. They agreed that net caloric counts for many foods are flawed because they don't take into account the energy used to digest food; the bite that oral and gut bacteria take out of various foods; or the properties of different foods themselves that speed up or slow down their journey through the intestines, such as whether they are cooked or resistant to digestion.

The process used to estimate calories for food was developed at the turn of the 19th to 20th century by Wilbur Atwater. It was a simple system of calculating four calories for each gram of protein, nine calories for each gram of fat, and four calories for each gram of carbohydrate (modified later by others to add two calories for a gram of fiber). Although it has been useful for approximating the energetic costs of metabolizing many foods, its shortcomings have been known for decades—and some nations, such as Australia, have dropped the system because it is "inaccurate and impractical,"

This is quite disturbing actually -- because a system is imperfect you just ditch it entirely?  I'm also curious about this writer and these scientists who act like this is groundbreaking new information they've just discovered.  I'll come back to this in a bit.  First, Stefani writes:

In a few small ways we can discern pinpricks of hope in the article, but in most ways it falls egregiously short of what a picture of true health really looks like.

Perhaps it falls short because the article, and the symposium referred to therein, had nothing to do with "true health".   The symposium, entitled Why a Calorie Is Not a Calorie and Why It Matters for Human Diets, was specifically about how total metabolizable energy present in foods may differ significantly with the energy that is "bioavailable" -- e.g. makes it in to the body in a form the body can process.    Stefani continues:

According to the article, calorie scientist specialists at the most recent American Academy of Science symposium convened in a panel to discuss the latest findings in calories and weight loss. Their opinion? That part of the reason weight loss has remained a pipe dream is not the fact that we’ve been emphasizing calories at all, but rather that we’ve been counting calories incorrectly.

Huh?  I didn't read that.  It wasn't a symposium on obesity.  Sure, they mentioned the implications -- in providing more accurate information to people so they can make better choices for themselves.   But they don't say anything about difficulties in avoiding and/or reversing obesity or that this is due to counting calories incorrectly.  Here's the lineup with links and a snippet of each summary.

Richard Wrangham, Harvard University:  Calorie Mismeasurement in Past and Present Human Diets

Food-processing is a human cultural universal whose positive effect for net energy acquisition has been increasingly clearly documented thanks particularly to the use of animal model systems and ileostomy patients. A critical next challenge is the quantification of energy consequences from food processing. This is important for research on human evolution because evolutionary success depends crucially on the ability to acquire energy ...

Klaus Englyst, Englyst Carbohydrates Ltd.:  Bioavailability of Dietary Carbohydrates

Carbohydrates typically represent the largest single contributor to energy, which is derived either directly through the metabolism of the available carbohydrates absorbed in the small intestine, or from the resistant carbohydrates fermented in the colon. Metabolic responses to, and energy derived from, carbohydrates is influenced greatly by the ingredients used and how the product has been processed. This presentation will discuss how in conjunction with in vivo studies dietary carbohydrates have been characterized analytically to reflect their nutritional attributes. ...

Peter J. Turnbaugh, Harvard University: Taking a Metagenomic View of Human Nutrition

The human gut harbors trillions of microorganisms that influence both sides of the energy balance equation, enabling dietary energy harvest and promoting fat deposition. Our recent studies have emphasized the unintended consequences our dietary choices can have on gut microbial ecology, and how studies in human cohorts and animal models can be combined to identify the mechanisms underlying the microbial component of human nutrition.

Stephen M. Secor, University of Alabama: The Metabolic Cost of Food Digestion and Its Determinants

An obligatory physiological response following feeding is an increase in metabolic rate stemming from the activities involved in the ingestion, digestion, absorption, and assimilation of the meal. The accumulated energy expended across these activities is referred to as the cost of digestion, heat increment of feeding, diet-induced thermogenesis, and specific dynamic action. Across a wide diversity of invertebrate and vertebrate species over a broad range of feeding conditions, this mandatory expenditure is equivalent to 5-30% of the meal’s energy. ...

Rachel N. Carmody, Harvard University 

Contributions of Food Processing to Dietary Energy Harvest

The caloric consequences of a highly processed diet have remained unclear, in part because few studies have evaluated energy gains associated with a processed diet independently of other lifestyle factors, and in part because the metabolizable energy values reported widely in the scientific literature and on nutrition labels suggest that food processing has little caloric effect. However recent controlled experiments in our lab employing animal models show that processing by thermal and/or non-thermal means contributes importantly to energy harvest from plant and animal foods. For instance, controlling for food intake and activity, omnivorous adult mice exhibited increased body mass outcomes when eating cooked and/or pounded sweet potatoes or cooked beef versus when eating these foods in unprocessed form. ...

Geoffrey Livesey, Independent Nutrition Logic Ltd. 

Improving the Atwater System: Balancing Accuracy and Practicality

Despite its limitations, use of the Atwater system is so pervasive that amending it to better reflect energy harvest poses a significant challenge. The presenter will review key shortcomings of the Atwater system, discuss the benefits and costs of implementing improvements with respect to scientific efficiency and public acceptance, and present thoughts on how we might consider modifying the Atwater system, balancing the goals of accuracy and practicality.

Aside:  Two of the presenters are evolutionary biologists from Harvard.  I realize it's water under the bridge, but did the AHS even try to reach out to either of these two last year?

The symposium raises fascinating issues about calories and my first thoughts are that perhaps we aren't really eating all that much more than we used to, but we're absorbing more due to cooking methods and processing.  It's hardly a far fetched notion.   It also raises the interesting moral question of how best to feed all humans on this planet -- more efficient calories would clearly be preferred, right?

But except for some recent semi-obsessiveness over gut bacteria (that may free up and contribute roughly 5% of energy in humans) the calorie conversation in the low carb and paleo communities has focused on hormones and mitochondria.  None of the issues raised here have any bearing on that discussion, they only address how much gets into the body.  Once inside the body, the calories are calories and it is known and should be taught in any reputable nutrition program, that the Atwater factors are both estimates and averages (e.g. long chain fats have more energy than medium chain fats, glucose can be "burned" aerobically and anaerobically, etc.).  Still, and somewhat surprisingly in many ways, these have held up well in metabolic ward studies that often involve liquid or uniform "muffin" diets for comparisons.  

One thing that I've mentioned here before is this fixation on thermogenesis.  It has been a while since I read Atwater's original work, but I'm not entirely unsure his factors didn't include thermogenesis.  Even if not, as warm blooded animals part of our basal metabolism is generating heat to maintain a relatively constant body temperature that is commonly elevated compared to our surroundings.  Heat generated in digestion/metabolism is just heat that doesn't need to be generated by oxidizing nutrients for the sole purpose of keeping us warm.  I've seen many studies looking at TEF and despite dramatic differences, many under metabolic ward conditions, no demonstrable differences are seen over a 24 hr period.  

So anyway, given all the pseudoscientific theories we're already having to deal with in the diet/exercise/supplement industry, my personal feeling is that the Atwater system as it is works just fine as an approximation.  If they tweak it to try to estimate the energy that would ultimately be absorbed it would leave waaaaay too much room for nutrition label hanky panky.  And in the end digestibility can highly variable, so we'd be back where we started to averages and estimates anyway.

One would think the Atkins veterans would be particularly "hip" to this!  After all,  none other than the esteemed scientists and doctors Volek, Phinney and Westman dished out dishonest advice to deduct all carbs for sugar alcohols in The New Atkins.

When it comes to low-carb foods, you subtract grams of sugar alcohols (including glycerin), as well as of fiber, from total grams of carbs to get the Net Carb count."

"Many low-carb products are sweetened with such ingredients as glycerin, mannitol, sorbitol, xylitol, erythritol, isomalt, lactitos and maltitol. ... Because sugar alcohols are not fully absorbed by the gut, they provide roughly half the calories that sugar does, although each one varies slightly. The incomplete and slower absorption results in a minimal impact on blood sugar and insulin response. This means that sugar alcohols don't significantly interfere with fat burning, making them acceptable on Atkins. ... Most people find that they can handle 20 to 30 grams a day without undesirable effects."

Now, they do acknowledge that there are some calories to be had ... but they skirt around acknowledging that those calories are effectively carbs.   Incredibly, they perpetuated the Atkins Nutritionals "missing carbs" FRAUD regarding glycerin -- aka glycerol.  AN tried to get glycerin classed as a fiber despite the fact that glycerol is easily absorbed and metabolized.  Then you have outfits like Julian Bakery who take great liberties with their reporting of digestible carbs and even Dreamfields with their nonsense proprietary "protected" carb structure.  Need I remind you who made his living hawking these products to you for years?

So one would do well to leave things as is and simply educate on the importance of eating minimally processed foods where food is abundant, and improve food efficiency to prevent starvation where it is not.  Otherwise, more hucksters are bound to come out of the woodwork.   Stefani clearly views this work differently.  

They don’t see issue with counting calories as it is. No, it’s best not to question the dominant paradigm, right? Instead of investigating what may be wrong in this big picture approach, these scientists are nitpicking whether there are, say, 200 or 220 calories in a slab of steak. Yes, certainly, that makes a difference. Thank you so much, AAAS.

This is clear calorie denial here.   She's also clearly ignorant of the amount of research that has been done on human nutrition in the realm of calories.  How else to explain this passage? (bolding hers)

Today, scientists are finally coming around to the idea that food burned in a lab is probably a little bit different in quality than food making it’s way through the human digestive system.

She's joking here, right?   While there's some new work here, it's not all new and there exist decades of research on exactly this topic!  As mentioned in Wrangham's snippet, a lot of this comes from trying to get nutrition into people with digestive impairments (e.g. ileostomy patients).  A note to the coconut oil fans, it has been used as a source of calories for those with fat malabsorption issues (because a significant proportion of its fatty acids do not need to be transported in chylomicrons).  Scientists coming from this perspective are not interested in "optimizing" inefficiency, so someone can eat 4000 calories without gaining weight.  Any Google Scholar search will net copious hits for Atwater Factors including this 1948 paper on the dynamic action of high carb and high protein diets.  Atwater aside, has Ruper missed the works of scientists like Eric Jequier and others on the fates of various nutrients once they are absorbed by the body.  So you'll have to pardon a little snark here regarding Ruper's smugness.

However: I would argue that fiber is more important because of the way in which it impacts therate of digestion, rather than calorie interference. Fiber can significantly slow the absorption of food, which in turn can prevent blood sugar from spiking. So that’s another angle that isn’t being considered here. At what rate is the food absorbed?

I would argue, who cares?  It is only in fairly massive overfeeding that this will make any difference at all (in terms of small amounts of carbohydrates converted to fat -- a calorie expensive process I might add).  I'm not talking health here, I'm talking what ultimately happens to that blood sugar, which is that once it's in the body it eventually gets burned for energy  (glucosuria in poorly controlled diabetes aside).  I'm reminded that many in the IHC -- especially the LC camp -- consider fiber to be overrated. I think it plays a significant role in satiety, not to mention the oft overlooked role in gut signalling, but can actually pose problems for those with high energy needs.  Stefani goes on to discuss hormones and nutrients (micro presumably), etc. and sums up with:

All of which is to say that the medical establishment en masse still has no respect for the conditions of a body into which the calories are introduced.

Which is an assumption, and nothing more, and not what this symposium was addressing.

How might a difference of 20 calories in a piece of steak actually matter at all when there remain vast disparities in metabolic health between insulin sensitive and insulin resistant individuals? That far and away determines a much larger proportion of a person’s weight status and ability to metabolize food than a difference of 20 calories a day.

Unscientific speculation at best, and I don't want to quote much more, you can go read for yourself.  As with her excitement that the scientists might be going in the right direction, I, too, was hopeful when Stefani says caloric intake matters.   She ends with some more inferences to health and how calorie counting won't make us healthy.   We get more of the same about how proper quality will bring quantity magically inline, which there are far too many examples she herself is friends with that demonstrate this to be more the exception than the rule.  As to calorie counting getting us healthy?  It sure isn't the only way, but in many cases it's all that's needed.  Prof. Haub got healthier eating Twinkies or do we just ignore non-paleo biohacks?  

Ya know, I got in a little Twitter tussle with Robb Wolf the other day over him tweeting a link to yet another quack doctor.  It got me to go back and re-read a few things he has written recently including part deux of his low carb/paleo series.  In summing things up he wrote:

Someday I’ll farm coconuts, but it wont happen until our medical and food production systems have dramatically changed and there are enough people who know about this Evolutionary Medicine schtick that our kids and grand kids will have things better than we have them.

Have things better than we have them?  It's not just Robb here, it's pretty much damned near this entire community that has it's collective head so far up the collective microflora house that comments like this seem praiseworthy and selfless.  Forget that the economics are such that younger generations are the first in basically the history of this nation that will not, as a whole, have it better than we have it.  We have it pretty darned fucking good, and you know I'm pissed because I just used that word.  Modern medicine is not perfect ... far from it ... but I have it to thank for the fact that I still have my mother, and have had her for the 20 years since she was diagnosed with breast cancer in 1993.  Or that we've had my father-in-law for almost as long since his diagnosis with prostate cancer and because his bypass surgery was almost a matter of routine when he had it 20 years ago.  His older brother just passed at 89.  Amongst our four parents they have known true struggle and hunger and starvation and malnourishment at various times in their youths.  People say I nit pick, well for crying out loud there's a paleo blogger out there who considers putting vinegar on your salad a transgression!  (Paleoista).  You and I might not even be here were it not for the Neolithic "evils" of agriculture and, dare I even say it, "industrialized" animal food production.   Sure, there are some people who should not eat grains, but please ... go witness TRUE poverty.  Go witness TRUE starvation.  People wonder why I don't just lose the rest of the weight and all manner of wondering about that and I let it roll off me because for crying out loud, my universe does not revolve around some pursuit of the arbitrary.  

Think about how ridiculous it is to desire to eat food that is inefficiently absorbed and/or inefficiently used for energy.   Or a community that longs for a return to the days before the "invention" of insulin to treat diabetes. There are far more healthy cultures thriving on high carb low fat (and I mean really low fat, like 10-15% fat low fat, not this BS we call low fat) diets than there are high fat low carb, and for the umpteenth time if you're not eating seal meat and brains in the frozen tundra, or whole coconuts in the tropics, as major parts of your diet, cut the crap!  Dining on grassfed prime rib in a heated restaurant or eating spoonfuls of coconut oil at your desk in an air conditioned office is not paleo or primal or whatever.  Nor, dear Stefani, is eating frozen veggies with balsamic vinegar normal.  I'm sorry.  I just tire of the food snobbery in this community while claiming to care about the health and well being of the masses.  I looked for local sources of grassfed beef and I would have to travel 30 miles to get it at the farm ... or I could pay up the wazoo at Whole Foods -- while the great unwashed must settle for being looked down upon for buying there's at Costco.  And best not buy that giant bag of rice or beans to go with because Grok didn't eat that, or gawd forbid they eat wheat because an obese lowcarbevangelist might snap pictures to put in his next post of pictures of how nobody cares about their health but him (as he pees out protein and oxalate crystals).

I swear if aliens came to this planet after humans became extinct and all that survived were the scrolls of paleo they would wonder how the human race lasted as long as it did ... what with all the rampant illness amongst former elite athletes and such.  Without modern medicine who would treat all the CrossFit injuries sustained by 100 lb women climbing rocks for the fun of it (instead of for food) and still searching for more?  The law enforcement officers on the paleo diet are still taking statins and other meds, which is responsible IMO.  Meanwhile Westman is going to coauthor a book on cholesterol with Jimmy Moore.  Is he aware of Jimmy's atrocious numbers?  It boggles ....

So please.  A little perspective sometimes?