Monday, July 9, 2012

AC Shoots Back, Hits Own Foot

Hyperlipid recalls a Mike Eades post:

Dr Micheal Eades in 2007:

"...what we’re talking about as a metabolic advantage is at the max about 300 kcal per day."

Ludwig's group using stable isotope doubly labeled water for Total Energy Expenditure assessment in 2012:

"During isocaloric feeding following weight loss, REE was 67 kcal/d higher with the very lowcarbohydrate diet compared with the low-fat diet. TEE differed by approximately 300 kcal/d between these 2 diets..."

This was the topic that put AC on my radar, as AC did his very best to battle Mike Eades over the topic of low carb in general and metabolic advantage specifically.  He even cites his posts about Eades in the post linked below, and of course claims victory in the debate.  One thing AC is unquestionably good at is beating his own drum.  I remember reading the AC/Eades debate thinking AC was out done, but I have a dog in the fight so who knows.

So what's AC all about?  First, he's published some books, including his online "Fat Loss Bible."  He seems to think a low glycemic index diet is the holy grail, and states he prescribes a dose of carbohydrate, from 75 up to 200 grams per day or so, based on client activity levels - which would make sense for lean healthy folks who may be doing endurance training.  AC thinks a calorie is a calorie, more work less food is the magic bullet.  His comments about overweight folks could be summed up as "they should get off their lazy behinds and work more, while eating less."
If you read his blog, you'll be exposed to some very good information on, for example, issues with grain consumption, the cholesterol myths, his dissection of "The China Study", and the foolishness of dogmatic vegans. Sadly though, you'll have to take that info mixed with a steady dose of "gee, aren't I smart and aren't they all stupid".  And you'll have to suffer through predictably sycophantic letters that all boil down to this meme:  "AC, you sure are great, I adore you and your work."
Lastly, you'll see if you follow AC that he's picked fights with a ton of folks in the nutrition and fitness world, which he seems to quite enjoy and which seemingly have done quite a lot to draw readers to his site.  It was perhaps a great marketing strategy, but he seems to like the head to head with others.  All the while, he's continuously gnawing on the "low carbers are not sufficiently rigorous with the science" (polite interpretation) bone.  He's quite ready to tell the world he's the only that can get the science right.

Here's AC's post about the JAMA study.
"Low-carb Metabolic Advantage Dogma (MAD) claims that at a given daily caloric intake, low-carb diets cause more weight loss than higher carb diets because of some magical mysterious freakazoid metabolic process that even the MAD believers themselves have never been able to coherently explain let alone provide actual evidence for."
I have only read one LC advocate who claimed a possible "metabolic advantage", most just say they lose weight and control hunger better, either on themselves or with their clients who need to lose body fat and regain health, using carbohydrate restriction.  Some have claimed that LC offered near magical benefits, and frankly - losing weight without hunger while restoring health is magic, especially for those who have tried calorie restriction, fat restriction and/or exercise and just ended up tired, grumpy, and having only lost some of the weight, which they rapidly put back on after giving up on their diet.  I don't care too much about the heretofore only speculated significance of LC metabolic advantage, and never invested much time in that idea - I know that folks switching to low carb spontaneously reduce caloric intake without needing to count calories or make a particular effort to eat less.  Despite Dr. Atkins claims that you could eat mountains of butter and lobster and steak - most LCers don't do that, partly because that's a lot of work and expensive to boot.

"Low-carb authors enthusiastically assured all and sundry that by cutting their carbs they would lose more weight at a given caloric intake, despite decades of research showing this claim to be utter hogwash. If the low-carbers truly believe the 'metabolic disorders' tale, where's the caveat in their writings that 'normal' folks can expect no such advantage? It's just a convenient excuse to try and slide out of a tight spot and salvage some credibility for their pet belief."
Let's just say he's right on this point - that calorie intake v. expenditure is all that matters - so what?  There are still many good reasons to use carb restriction, backed by good science, and particularly so for folks who have a significant excess of body fat.  For those that respond well to carb restriction, intake goes down, activity increases, and health is restored; "it's all good."

"Well, that's a most interesting avenue of denial, considering that "metabolic defects" only became important to the low-carbers after it was pointed out to them that their diet repeatedly failed to show any weight loss advantage in tightly controlled ward studies."
There are not many tightly controlled ward studies, and many of the ones that exist focus on very low calorie intake.  Below a certain daily intake of calories, a low intake percentage of carbs no longer helps by reducing glycemic overload - folks aren't eating enough to induce glycemic overload.  This is not debated.  However, these studies show that on a semi starvation diet (~1200kcal/day), those eating adequate protein and fat (i.e., low carbs) suffer from much lower reported hunger levels.  This is why met ward studies don't always show what matters - if you control what folks eat and maintain low calorie intake, the LC advantage does not manifest itself for a long time, EXCEPT that folks feel better and have less hunger.  Put those folks in the "wild" and it's easy to guess that the LCers experiencing less hunger would eat less than the high carb crowd, and that is exactly what is observed.

This is what AC misses in his analysis of the study, but he wasn't the only one:
"Cornier and his team compared diets of lower- and higher-carb content and found those with insulin resistance lost more weight on the lower carb diet. The Cornier et al study was not a ward study, and so the short term results again could be (and in all likelihood were) explained by differences in caloric intake. The way to eliminate this possibility would be to ensure the two groups really did consume isocaloric diets by placing them in a metabolic ward."  AC continues:  Which is most interesting when one considers absolutely no such advantage was observed during the study. In the researchers' own words:
(AC is quoting from the study here)"Body weight did not differ significantly among the 3 diets (mean [95% CI], 91.5 [87.4-95.6] kg for low fat; 91.1 [87.0-95.2] kg for low glycemic index; and 91.2 [87.1-95.3] kg for very low carbohydrate".
AC continues: "Bodyweight was virtually identical during all three isocaloric diet phases which to me, as a rational indvidual whose head has never been embedded in his culo, quickly refutes the famous low-carb claim that greater weight loss will occur on a low-carb diet at a given caloric intake. At the caloric level calculated by the researchers to maintain weight, the low-carb diet did exactly what the other diets did - it maintained weight. It did not magically produce further weight loss while the other diets simply maintained the status quo."

The authors of the study responded (posted at Free the Animal):
“The point is that 4 weeks isn’t long enough to translate a 300 kcal/day difference into statistically significant weight change, especially when one considers that body weight normally fluctuates by a kilogram or two though the course of a week, based on differences in hydration status, the time of the last bowel movement, etc. We’d need 6 months to reliably see this effect. Nevertheless, there was a slight, and not statistically significant
difference in the hypothesized direction, with body weight highest on the low fat diet (data included in the results section).”

IOW, if the result is sustained for one month, the "maintenance LC" dieter would maintain a 300kcal/day advantage in metabolic rate which would equate to "burning" 9000kcal, or 2.5 pounds per month.  That my fiends is nothing to sneeze at for a person who desires to maintain a hard fought weight loss.
AC also delves into the individual variation portion, since not everyone did as well on the LC.  He makes the blinding flash of the obvious, which is that not all human bodies respond alike.  To which, I would respond in this very scientific way - so what?   Of course there's individual variation. That also shoots holes in the calorie is a calorie argument.
AC points to another not serious issue:  "Meaning that if you adopt a low-carb diet expecting an increase in metabolism, based on the results of this study, there's a very strong possibility you'll be sorely disappointed. Heck, you may just suffer the same fate as other well known purveyors of this belief and be forced to don a belly-restraining girdle to hide the contradictory evidence hanging from your waist."
In that case, I would recommend that you stop trying low carb, and/or restore your discipline to doing low carb.  That doesn't by any means indicate that trying LC might buy you the 300, or more, kcal/day this study indicates can happen on a maintenance diet if you eat enough fat and protein to keep your metabolism happy and humming.

Of course AC beats the low thyroid drum - but like any discrete marker, it's only a problem if it's a problem.  IOW - would you eat more carbs and get fat and feel bad so you could improve your thyroid levels?  And if you try LC for long enough, and if you experience the thyroid decrease that can be associated with long term carb restriction, and you don't feel good any longer, well, I would suggest trying something else.  Or trying intermittent fasting with low carb and bigger individual meals.  Or occasionally carb binge to see if that convinces the body there's no starvation going on (thought to the be the reason for the thyroid decrease).  Frankly, low thyroid is already an issue for obese people, so losing weight by LC and still having low thyroid wouldn't be a show stopper.
AC also beats the inflammation issue, citing the test subject's increased levels of CRP and cortisol.  These are not ideal, but most folks' health will be much better if they sustain weight loss.  Further, longer term studies show good results with inflammatory markers.  This is a concern, but not a show stopper by any means.
"So much for a metabolic advantage. If heightened catabolism and inflammation constitute an 'advantage', then I'll give it a miss, thank you. I'll stick to my highly disadvantageous regimen of intelligent nutrition and regular exercise that sees me maintain with minimal fuss the kind of single-digit bodyfat levels most low-carb devotees will only ever be able to dream about."
Like most of us in this game, AC should remember that just because it works for him, does not mean it works for everyone.  If I saw him, I'd drink to AC's success in looking good, and I hope he helps a million folks reach their fitness goals.
There's no reason, though, for AC to keep grinding the ax against LC when there're so many folks who are very ill, very heavy, and can get help from a low carb diet.  This is not refutable.  Many people have worked wonders to improve their lives with LC.  Sometimes, AC should let go of the bone and let the good be good.  Something does not have to meet every test of scientific truth to be useful information, a fact for which I'm quite thankful because the science of humans and diet is anything but settled.
AC closes with 5 points, of which the last four are points I have made in my own blog.  We see many things the same, with the exception of his terrier on a bone attitude about carbohydrate restriction, and his propensity to engage in squabbling.

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