Monthly Archives: October 2012

Exenatide and tapeworms, Op. 116

Posted on October 29, 2012 | 1 comment

The great Dr. Schoeller can polish a turd like no other.  Dale Schoeller’s claim to fame is his extensive work on one of the best ways to measure total energy expenditure in free-living individuals: doubly-labeled water.  In doubly-labeled water, subjects drink stable isotope-labeled water; instead of hydrogen + oxygen = H20, the stable isotope-labeled water is deuterium + oxygen-18 = D218O.  Deuterium is excreted just like hydrogen, in water as urine & sweat.  Oxygen-18 is excreted just like oxygen, in water and carbon dioxide.  So the subjects lose deuterium & oxygen-18 in water at equal rates, but only oxygen-18 in carbon dioxide; so this technique basically measures carbon dioxide production, which is proportional to energy expenditure.  Clever. 

Being that Schoeller practically invented the technique, his interpretation of these total energy expenditure data are not flawed, but that’s not where he went astray.

Alterations in energy balance following exenatide administration (Bradley et al., 2012)

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Posted in Advanced nutrition, diet, Energy balance, insulin

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“An adult conversation” about the Look AHEAD study

Posted on October 21, 2012 | 1 comment

Extra! Extra!    Read all about it!  (after you sign up for the new EMAIL NOTIFICATIONS on the right)

Moderate weight loss alone doesn’t lower heart disease risk in diabetics, study shows
Diabetes study ends early with a surprising result
NIH trial of lifestyle intervention for type 2 diabetes stopped for futility after 11 years

Notice none of the headlines read “Low fat diet is not heart-healthy for diabetics,” but that’s exactly what the latest epic fail demonstrated.  Reminiscent of the Women’s Health Initiative (circa 2006), the Look Ahead study tested a long-term low fat diet in diabetics.  If a protective effect had been shown, this study would’ve gone done in the history books as definitive proof that a low fat diet is superior.  But it wasn’t, and unfortunately that probably won’t count as anything for the opposition.  In brief, the planned 14 year study was stopped after 11.5 years because cardiovascular events weren’t lowered by the low fat diet (and might even have been increased; the manuscript hasn’t been published [yet?]).

The Women’s Health Initiative, which cost taxpayers something in the ballpark of $625,000,000 (six hundred twenty five million dollars > a half billion), showed that reducing dietary fat by 8 percentage points (from 37.8% to 28.8%; a 23.8% reduction) for 8 years had no effect on heart health and was even detrimental for people with CVD at baseline.  I repeat: CVD patients assigned to the low fat dietary intervention experienced more cardiovascular events than those in the control group (you heard it here first).  But for some reason, the Look AHEAD researchers thought they might get a different result if they tried this in diabetics?  A low fat high carb diet in patients with bona fide carbohydrate intolerance?  really?

REALLY?

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Posted in Advanced nutrition, diet, Dietary fat, empty calories, insulin

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Metabolic rate per se

Posted on October 17, 2012 | 1 comment

I’m switching to a new email sign-up service and have no idea how to transfer my current list of subscribers.  If you’d like to continue receiving updates, please sign-up again on the right.

Admittedly, the effect of diet on metabolic rate is small (i.e. statistically non-significant in most cases), but its incredible consistency across space and time suggest it could be true.  And given the difficulty of maintaining a reduced body weight after dieting, it might even be important.  The following studies are examples of widely differing subject populations in various metabolic conditions; yet the effects of diet on metabolic rate exhibit a phenomenal degree of similarity.

disclaimer: I don’t know what’s more important – metabolic rate per se, the diet behind it, or the resulting hormonal adaptations.  All of the diets that are associated with a higher metabolic rate are also predicted to result in lower insulin levels and higher fat oxidation.  Thus, we are left with a triumvirate of diet, hormonal milieu, and energy expenditure… all of which are important for body composition and quality of life.

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Posted in Advanced nutrition, diet, Dietary fat, Energy balance, Exercise, insulin, Protein

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[ketogenic] elite artistic gymnasts

Posted on October 12, 2012 | 6 comments

Before you say anything, “elite artistic gymnasts” could probably beat you in a race running backwards.  (with you running forwards.)  They are elite athletes.  And given a sufficient keto-adaptation period, they perform better sans carbs.

Ketogenic diet does not affect strength performance in elite artistic gymnasts  (Paoli et al., 2012)

This study looked at body composition and various performance measures before and after 30 days of a very low carbohydrate ketogenic diet (“VLCKD,” < 25 grams of carbohydrate per day) or a normal diet (“WD,” > 250 grams of carbs per day).  25 grams of carbs is very very low, less than Atkins and Kwasniewski.  On the other hand, 41% protein is pretty high.

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Posted in Advanced nutrition, diet, Dietary fat, empty calories, Energy balance, Exercise, insulin, Ketosis, Protein, TPMC

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The Laws of Energy Balance FTW!

Posted on October 9, 2012 | 3 comments

Weight loss maintenance is not determined by calorie intake… or physical activity… but by The Laws of Energy Balance FTW!!!

Odd, the sensation I felt when reading this news release (gloating?).  As reported at a meeting of the Obesity Society, results from the Utah Obesity Study of gastric bypass patients 2 and 6 years after surgery.  By the 2 year mark, they lost over 100 pounds, or 36% of their starting weight (went from 296 to 189 pounds).  Energy expenditure declined from 2201 to 1736 kcal/day.  Food intake went from 2085 to 1638 kcal/day.  (Hint: it’s no coincidence that energy expenditure and food intake declined to the exact same degree.)  Physical activity and fitness levels increased.

By the 6 year mark, they still weighed 29% less than their starting weight.  N.B. that’s an amazing level of success, it’s virtually unheard of in diet intervention studies.  +1 for gastric bypass; -1 for nutrition.

Here’s what piqued my interest: during the gradual increase from 189 pounds to 210 pounds, which occurred between years 2 and 6 post-surgery, the most significant factor associated with weight regain was not calorie intake or physical activity… it was metabolic rate.  This represents another fail for “eat less move more,” and a win for the Laws of Energy Balance.

So what’s this got to do with The poor, misunderstood calorie?

what we know about metabolic rate:

1)      It’s invisible.

2)      Fructose vs. The Laws of Energy Balance (circa December, 2011): sugar-sweetened beverages can cause fat gain, not by providing excess calories, but by reducing metabolic rate.

3)      Holiday feasts, the freshman 15, and damage control (circa January 2012): overeating a high protein diet causes less fat gain than overeating anything else because it increases metabolic rate.

4)      Missing: 300 kilocalories (circa July 2012):  after losing weight, subjects assigned to the low carb diet maintained a higher metabolic rate than those on an isocaloric low fat diet.

“Eat less move more” is not the answer.  But eating less sugar, more protein, and fewer carbs might be.  Nutrition matters.

calories proper

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Posted in Advanced nutrition, diet, empty calories, Energy balance, gastric bypass, Protein, Sugar, TPMC

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Protein bar takedown, part III (or V)

Posted on October 6, 2012 | 4 comments

No more pretense or cute backstory; I just like reviewing ingredient profiles of protein bars.  It’s a hobby of mine:
Candy in disguise, Op. 73 (circa April 2012)
Decepticon Promicor (soluble corn fiber), Op. 81 (June 2012)
Candy in disguise II, Op. 87 (July 2012)
Protein bar round-up, take II (September 2012)

See?

This is a review of Netrition’s “highest rated” bars.  Important notes about this category: these are not necessarily “new” protein bars, or even the bars everyone buy (“best sellers”).  They are the bars everyone who votes like the most.  They’re not the healthiest either… but some come close.   Continue reading →

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Posted in Advanced nutrition, diet, Dietary fat, empty calories, fiber, gluten, Protein, Sugar, Uncategorized

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Missing: 300 kcal… AGAIN!

Posted on October 3, 2012 | 6 comments

Or, the curious perils of crappy sleep, part II: calorie-thieving gnomes.

In part I of the Crappy Sleep series, we discussed, among other things, the malevolent metabolic effects of the most utterly abnormal sleep structure (28-hour days, 6.5 hours of sleep per night [~5.6 hours / 24 hours], and dim lighting during the days).  In this study, the sleep was disrupted to a physiologically relevant degree for two weeks: 8.5 vs. 5.5 hours per night; in a cross-over study.

In part I of Missing calories, we discussed the effects of 3 different diets on metabolic rate after weight loss.  In this study, energy balance was assessed during 2 different sleep regimens in dieters in a CROSS-OVER STUDY.  If you haven’t guessed it, I believe a well-designed and executed cross-over study is superior, necessary, and essential for most metabolism-related studies.

Insufficient sleep undermines dietary efforts to reduce adiposity   (Nedeltcheva et al., 2010)

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Posted in Advanced nutrition, diet, Energy balance, Protein, TPMC

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