Tag Archives: insulin

Dopamine

Posted on June 22, 2013 | 18 comments

“When we block the D2 receptor in humans, it is expected they will develop glucose intolerance, obesity, and sedentary behavior.” -Jane Plain, in her series on The physiology of body fat regulation.  It’s probably true.

Randomized pilot study of cabergoline, a dopamine receptor agonist: effects on body weight and glucose tolerance in obese adults (Gibson et al., 2012)

Cabergoline is primarily used to treat prolinactinoma, or prolactin-secreting tumors.  In women (& men apparently), prolactin stimulates milk production; in men, it is associated with the refractory period after orgasm.  In both genders, dopamine inhibits prolactin secretion.  Cabergoline targets the D2 receptor, but it’s a dirty drug.  It’s used off-label for gyno and to improve sexy times (Kruger et al., 2003 <– yes, that was actually tested).

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Posted in Advanced nutrition, Bromocriptine, Cabergoline, Dopamine, insulin, Leptin

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Eating in the Absence of Hunger

Posted on June 17, 2013 | 12 comments

Hat tip to Jane Plain and her ongoing series on “The physiology of body fat regulation” for citing this study as it provides a rather interesting insight into the psychoendoneuropathophysiology of the obese condition.  Eating in the Absence of Hunger.  

Caloric compensation and eating in the absence of hunger in 5- to 12-y-old weight-discordant siblings (Kral et al., 2012)

They were all full or half, weight-discordant, same-sex siblings and each sibling pair had the same mother; same mitochondrial DNA, shared a womb, etc.

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Posted in Advanced nutrition, chocolate, Dietary fat, empty calories, Energy balance, insulin, Ketosis, TPMC

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Are carbs stored as fat?

Posted on May 25, 2013 | 65 comments

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, 2013; full 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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Posted in Advanced nutrition, diet, Dietary fat, Energy balance, fat, insulin, TPMC

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Liver is evil but need not be punished. SFAs.

Posted on April 17, 2013 | 25 comments

What to serve with a liquid lunch, and a recipe for chocolate.

It’s like a feed forward downward spiral.  If you don’t eat saturated fat & MCTs prior to imbibing, then liver intentionally makes more PUFAs for the alcohol-induced burning ROS to molest.  Liver is evil but need not be punished.  SFAs.

Brief background: (Kirpich et al., 2011 & 2013)

Researchers studying alcohol in rodents know where they’re going and like to get there fast.  70 drinks per day fast.  Granted, rats metabolize faster than humans so it’s likely a little less… but a little less than 70 is still a lot of sauce.

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Posted in Advanced nutrition, diet, Dietary fat, empty calories, Energy balance, fat, insulin, pair-feeding, Sugar, TPMC

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salt makes you thirsty, soda makes you hungry.

Posted on April 3, 2013 | 5 comments

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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Posted in Advanced nutrition, diet, Dietary fat, empty calories, Energy balance, fat, Fructose, Leptin, Sugar

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Obesity is not permanent

Posted on March 27, 2013 | 15 comments

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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Posted in Advanced nutrition, diet, Dietary fat, empty calories, Energy balance, fat, Leptin, Sugar, TPMC

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How to define a “healthy” diet. Period.

Posted on March 13, 2013 | 7 comments

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

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Mediterranean Diet Fail – Nutrition Disinformation, Part I.

Posted on February 27, 2013 | 5 comments

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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Posted in Advanced nutrition, diet, Dietary fat, empty calories, Energy balance, fat, Fish, gluten, Grains, insulin, mortality, Protein, Sugar, TPMC

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Paleotard, meet potatotard, Op. 132

Posted on February 23, 2013 | 12 comments

(credit to Dylan and Woo, respectively, for introducing me to those terms)

Empty calories – the potato. 

While it has a decent amino acid profile, with only 3 grams of protein it’d take a diabetic amount of potatoes to fulfill your daily protein.  By “diabetic,” I mean about a thousand grams of starch.  potatoes are just as glycemic as white bread.

potato

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Posted in Advanced nutrition, diet, Dietary fat, empty calories, Energy balance, fat, gluten, Grains, insulin, mortality

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Fat mitochondria

Posted on February 17, 2013 | 14 comments

No, not heavyweight powerhouses.  Mitochondria IN fat cells.
electricity is required for your space heater, not your long johns.

mito

At first glance, the mere presence of mitochondria in adipocytes seems perplexing.  On one hand, there’s tons of fat to burn, so why not have the capacity to do it?  Well yeah, but on the other hand, adipose doesn’t do very much.  It doesn’t contract like skeletal muscle or crank out glucose like liver.  Mitochondria in BAT is understandable, to generate heat and what not.  electricity is required for your space heater, not your long johns.

My best guess is that adipose tissue mitochondria are there to do something else – make shorter acyl chained FA’s, or free radicals, etc., to signal something.  Just not primarily to generate energy.

But drop an anvil on adipose tissue mitochondria and you get some interesting mice indeed.  Impossible mice.

TFAM – in brief, the enzyme that goes by the acronym TFAM makes mitochondria work.  Global TFAM KO is lethal.  But adipose tissue (AT)-specific KO is interesting.  Uncoupling goes through the roof and fat literally burns away.  kind of***.

Adipose-specific deletion of TFAM increases mitochondrial oxidation and protects mice against obesity and insulin resistance (Vernochet et al., 2012)

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Posted in Advanced nutrition, Dietary fat, Energy balance, fat, insulin, muscle

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