Tag Archives: carbohydrates

Summer is fattening. Don’t do it in winter.

Seasonal eating proper

More on seasonal eating in what appears to be the primary model for its justification for use in humans – hibernating mammals.

How it goes, or so they say: in summer, hibernators massively overeat, including carb-rich foods, in order to generate muscle and liver insulin resistance, so as to promote body fat growth.  The long light cycle reduces evening melatonin, which pushes back the usual nighttime peak in prolactin, which causes an abnormal resistance to leptin, which induces hypothalamic NPY and subsequent carbohydrate craving.  Ergo, summer is fattening.  In today’s day, increased artificial lights guarantee year-round pseudo-summer; and we no longer experience the benefits of the short light cycle: longer sleep times (akin to hibernation) and fasting – either complete fasting as in hibernation, or pseudo-fasting, ie, a ketogenic diet.

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Silent Leptin Resistance

Conventional leptin resistance has something do with obesity.  It is known.  Silent leptin resistance is … err … complicated. 

Divide and conquer

Fructose-induced leptin resistance exacerbates weight gain in response to subsequent high-fat feeding (Shapiro, Scarpace, et al., 2008 AJP)

A remarkable 60% fructose diet fed to rats for 6 months had absolutely no effect on energy balance.  Nil. QED.
Fig 1

Food intake and body weight were unaffected because the levels of and sensitivity to endogenous leptin were identical in both groups.

Enter the Dragon

Enter the Dragon

“Silent Leptin Resistance” – The fructose-fed rats are, however, profoundly resistant to the satiating effects of Metreleptin (a pharmaceutical grade injectable leptin analog):

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Are carbs stored as fat?

Hint: “no”

DNL proper.

Lots of metabolism talk below, but first a brief intro.  My “muse,” if you will.

Taubes’ recent article in the BMJ (Taubes, 2013full text) generated some interesting feedback.

In the original article, Taubes basically re-states his philosophy on obesity.  Nothing new.  But one rebuttal by Cottrell got under my skin (Cottrell, 2013), and Taubes’ response was woefully inadequate.

Cottrell [sic]: “A third incorrect assertion is that obesity can be attributed to the conversion of carbohydrate to fat. This is an unsatisfactory explanation of obesity, because this route is a minor pathway to depot fat in humans, even under conditions of substantial overfeeding of sugars to obese subjects.  An unproved assumption is that the hypothetical diversion of carbohydrate energy into fat storage leaves the subject hungry, thus stimulating overeating.”

strawman

Cottrell set up a straw man and handily took it down.  The primary mechanism whereby excess carbs contribute to obesity is via insulin’s effects on adipose tissue.  Even if you’re eating very little fat, insulin will cause it to get stored.  Insulin is very good at this – it is actually far more potent at stimulating fat storage than it is at stimulating glucose uptake (eg, Insulin vs. fat metabolism FTW).  Cottrell’s straw man is that excess carbs themselves are stored as fat.  This does not occur to any appreciable extent in humans.  Here is why I believe that to be true, from one of most insightful and informative studies on the topic IMHO.

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salt makes you thirsty, soda makes you hungry.

As previously discussed, DRINK was a randomized intervention study that gave children either regular or diet soda for a year and surprise surprise, the regular soda drinkers gained about more body fat than the diet soda drinkers (de Ruyter et al., 2012).  And in the follow-up, with an opposite study design, overweight & obese children who continued to drink regular soda gained twice as much weight as those who cut their intake (Ebbeling et al., 2012).  There was no apparent black box in the latter study as the kids who stopped drinking soda also decreased their intake of other foods…

-does not compute-fructose

wait a minute … By switching from regular soda to diet, you just end up compensating by eating more of something else, right?  My initial response to that has always been that it doesn’t matter – ANYTHING else is better than a straight shot of 100% HFCS (+ some other chemicals).  But those kids didn’t do that.  they ate less of other foods.

 

Does HFCS soda make you eat more?

A recent study has put a little more fuel on this fire.  Similar to the abovementioned two, it’s not a sophisticated study designed to accurately assess the impact of regular soda on appetite, satiety, hunger, etc., but it supports the theory that diet soda negative calories are NOT compensated for by eating more of something else.


Food and beverages associated with higher intake of sugar-sweetened beverages (Mathias et al., 2013)

It was another big cross-sectional NHANES study that simply asked how much regular soda, diet soda, and other foods kids were eating.Mathias data 1

They showed that as soda intake increased, so did total calories, which could simply mean the soda was adding calories to their diets.  This would indirectly support the opposite of the above mentioned theory, namely, that soda calories aren’t compensated for.  But it gets better (or worse, depending how you look at it):Mathias data 2

soda didn’t simply add to the total calorie intake.  More often than not, calorie intake increased above and beyond that contributed by the soda.  And it wasn’t just that bigger kids were drinking more soda and eating more food – these data were controlled for body weight.  The authors estimated that for every 100 kcal of soda drank, an additional 36 – 86 kcal of food was eaten.

salt makes you thirsty, and now soda makes you hungry?

 

calories proper

 

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Obesity is not permanent

Take a group of obese people (> 250 lbs) and put them on a massive calorie restricted diet.  They lose weight and metabolic rate plummets.  Weight loss fail?  In most cases, yes.  But a recent study showed that the decrepit post-weight loss metabolic rate gradually improves in parallel with an increase in dietary fat ingestion to such a degree that even after two long years: totally food intake was almost back to normal, energy expenditure improved, and all this happened despite continual weight loss.  In other words, obesity is not permanent. 

creme brulee

Decreased energy density and changes in food selection following Roux-en-Y gastric bypass (Laurenius et al., 2013)

Statistically speaking, no diet on Earth comes close to RYGB in terms of weight loss success.  Long term.  Seemingly permanent.  It’s the closest thing to a cure we’ve got.

Laurenius

Body weight is down by 30%, and energy expenditure is rising faster than a speeding bullet.  because food intake is increasing while body weight is dropping – they’re probably more active too ** weight loss than more exercise –

But there’s a more mystical aspect to RYGB that warrants attention.  (it could be the increasing fat intake, but for now let’s just say it’s RYGB per se).  According to this pearl, weight loss of only 10% via diet alone causes energy expenditure crash by 394-500 kcal/d, and physiological replacement of leptin via subcutaneous injection can increase this by 234-454 kcal/d (Rosenbaum, Murphy, Heymsfield, Matthews, and Leibel, 2002).

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How to define a “healthy” diet. Period.

Whether you’re strictly adhering to a diet or just doing your own thing, if year after year your GP is prescribing more and more medications to stave off morbidity and keep you intact, then the diet you’re following is most likely Fail.  The same is true if your body weight is creeping upward or your quality of life is creeping downward.lunchables

The glaring Fail of all 3 diets in the recent Mediterranean Diet Study for the medications criteria threw up a huge red flag.  As a brief refresher, at baseline and 5 years later, prescription medication usage was as follows:

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Mediterranean Diet Fail – Nutrition Disinformation, Part I.

Do not get your hopes up, do not pass GO!  do not collect $200.  The Mediterranean Diet.  Fail.

Primary Prevention of Cardiovascular Disease with a Mediterranean Diet (Estruch et al., 2013)

This is one of the biggest diet studies we’ve seen in a while, and no doubt it was a very good one.  It very effectively put the Mediterranean Diet to the test.

I felt compelled to write about this study out of fear for the nutrition disinformation that it would likely inspire.  The Mediterranean Diet is associated with all good things, happiness, red wine and olive oil; whereas the Atkins Diet is associated with artery clogging bacon-wrapped hot dogs and a fat guy who died of a heart attack.  Nutrition disinformation.

If you ran a diet study with 3 intervention groups for 5 years, and by the end of the study everybody (in all 3 groups) was on more prescription medications, would you conclude any of the diets were “healthy?”  If so, then we should work on your definition of “healthy.”

Study details: big study, lasted roughly 5 years, and the diet intervention was pristine.  Mediterranean diet plus extra virgin olive oil (EVOO) vs. Mediterranean diet plus nuts vs. low fat control.  They even used biomarkers to confirm olive oil and nut intake (hydroxytyrosol and linoleate, respectively).  Compliance was good.

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Protein bar takedown, part III (or V)

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

Candy in disguise II, Op. 87

Rundown on a few new protein bars, pro’s & con’s, etc.

Perfectly Simple by ZonePerfect
The catch: 3 new bars with 10 or fewer ingredients.  All are gluten-free and have 10 grams of protein.

as the number of ingredients increases, so does the sugar

Sweeteners:
Peanut Crunch: “invert evaporated cane juice”
Toasted Coconut: “invert dried cane syrup”
Cranberry Almond: “date paste”

It takes more sugar in the form of “date paste” (Cranberry Almond, 19 g sugar) to compensate for the lack of “invert evaporated cane juice” (Peanut Crunch, 14 g sugar) or “invert dried cane syrup” (Toasted Coconut, 16 g sugar).  Invert sugar is basically table sugar (sucrose) that has been broken down into glucose & fructose.  1) It’s sweeter, which is why you need less of it; and 2) it’s essentially identical to high fructose corn syrup = used in everything from candy and crackers to cigarettes and soda.  Not good.

Active X Energy Bar
Kosher, organic, but not gluten-free.

Pro’s: less sugar and more fiber than ZonePerfect’s Perfectly Simple. 

These bars rely on the sweetener brown rice syrup which is primarily glucose (significantly less fructose than invert sugar), but it’s complimented with agave (significantly more fructose than invert sugar)… end result?  Organic high fructose corn syrup (a polished turd).

Good2Go bars

High protein, moderate sugar, and preservative-free.

These bars are sweetened with honey, brown rice syrup, invert sugar, and a little coconut sugar.  These bars have more protein and less sugar than both Perfectly Simple and ActiveX.

Last but not least, my personal favorite in the “coolness” department: Chapul.

Pro #1: they owned it!  “sugar” actually appears in the list of ingredients.

Pro #2: while it’s only 6 grams of protein, you’ll never guess where it comes from… crickets!  Yes crickets.  Baked, then ground into a fine powder.

Con: the most sugar and least protein of all.

To put this all into perspective: relative to the nutritional profile of Quest protein bars, these noobs pale in comparison.

Conclusion: candy in disguise.  just sayin’.

calories proper

The easy diet diet, Op. 72

Regular followers of this blog (all 3 of you) know I think positively about carbohydrate-restricted diets.  In randomized controlled intervention studies, low-carb diets are a little better most of the time compared to low calorie and low fat diets (note the italics).  They are healthier and there is probably no end to the benefits of chronically lower insulin levels.  The only relevant disadvantage is that [I thought] such a diet requires too big of a change for most peoples lifestyle…  however, this might not be the case.  In light of some recent [relatively unscientific] findings, that change might not be so big after all.

In one study, Feinman and colleagues (Feinman et al., 2006 Nutrition Journal) surveyed a group of low carb dieters from the “Active Low-Carber Forum” about their diets.  There was no formal subject recruitment or randomization; it was just a bunch of people who were following various low carb diets.  The only requirement was that they were actually following a low carb diet for weight loss.  For starters, there were a LOT of people who lost a LOT of weight: 62% of ~86,000 participants lost at least 30 pounds and kept it off for over a year (I know I know, it’s possible that people who lose a lot of weight are selectively more likely to participate on this particular forum [this study is confounded out the wazoo but still had a few pearls]).

What I found most interesting was what these people said were their biggest dietary changes.  The top 2 were, not surprisingly, avoiding sugar and starch.  Number 3 was drinking more water.  So to sum up the top 3 changes: basic healthy dieting 101; not drastic lifestyle alterations.

Number 4 was the biggie: most people increased their green vegetable intake by over half… not bacon, hot dogs, and red meat… leafy greens.  This is great (just think of all those micronutrients).  They weren’t counting calories or replacing everything in their refrigerator; they were avoiding sugar and eating more leafy greens.

leafy greens: winner

sounds easy, right?  Of course eating more protein and fat also occurred, but it wasn’t a universal requirement: only 5% reported increasing beef, butter, and bacon… instead, people just ate a little more of whatever was most convenient for their lifestyle.

This study changed my view.  These people lost over 30 pounds on low carb and kept it off for over a year without making any huge changes.

Another more recent study (Kirk et al., 2012 Journal of Pediatrics) was a diet intervention study in obese children.  They compared a low carb diet (LC), low glycemic index diet (RGL), and a portion controlled diet (PC).

It’s hard to put kids on a low carb diet.  Indeed, adherence to the low carb diet was horrific, less than 30% at 3 months and down to 20% at 6 months (figure below on the right).  But comparing this to the figure on the left is astonishing.  Despite adherence of only around 25%, low carb dieters had the biggest reduction in body fat.  It’s not until adherence was nil that the kids starting gaining weight back.

weight loss vs. adherence

What does this say about low carb?  it’s the easiest diet in the world, even if you can barely follow it!  25% adherence to a low carb diet resulted in greater fat loss than 80% adherence to the other diets.

You might just be better off half-assing a low carb diet than strictly adhering to any another one-

calories proper