Category Archives: Sugar

Does junk food make you lazy?

From Times LIVE: “Does junk food make you lazy?” 

“A diet rich in processed foods and fat – and the extra weight that comes along with it – may actually cause fatigue, a lack of motivation and decreased performance, according to a recent study involving lab rats… excessive consumption of processed and fat-rich foods affects our motivation as well as our overall health.”

(this is categorically false as both diets used in the study being discussed were very low in fat.)

And from Psych Central: “Rat study shows junk food can make you lazy

The theory itself isn’t too far-fetched: a crap diet can cause weight gain and reduced energy expenditure, or a tendency to minimize any kind of physical activity… instead of: “’laziness’ causes obesity.”  And whether or not it’s true, unlike what some would have you believe, this wasn’t the study to prove it.

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Insulin, sympathetic nervous system, and nutrient timing.

Insulin secretion is attenuated by sympathetic nervous system activity; eg, via exercise.  Theoretically, exercising after a meal should blunt insulin secretion and I don’t think this will lessen the benefits of exercise, but rather enhance nutrient partitioning.   And this isn’t about the [mythical?] post-workout “anabolic window.”

Sympathetic innervation of pancreas: norepinephrine –> adrenergic receptor activation = decreased insulin secretion & increased lipolysis (Stich et al., 1999):

Stich insulin

Stich CAS

note how quickly catecholamines are cleared upon exercise cessation

Stich NEFA

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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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Liver is evil but need not be punished. SFAs.

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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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.


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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Insulin vs. fat metabolism FTW

Insulin is there to grow fat tissue for the obesity epidemic, not replenish glycogen after yoga.

Teaser: insulin-induce hypoglycemia can get deadly quite fast, and there is no equivalent for the effects of insulin on fat.  However, the effects of insulin on fat are 100 times more powerful.

Background: Hormone sensitive lipase (HSL) responds to insulin by inhibiting lipolysis.  It halts fat burning.  It got its name because it’s THEE most hormone-sensitive lipase in the body.  The hormone about which we are speaking is of course insulin.  And the enzyme, or at least one of the enzymes as it were, is HSL.  To be clear, it takes very little insulin to inhibit HSL.  Just a dollop, in fact.

Effect of very small concentrations of insulin on forearm metabolism.  Persistence of its action on potassium and free fatty acids without its effect on glucose.   (Zierler and Rabinowitz, 1964)

Expt 1.  Since we’re all about jabbing people with insulin lately, let’s get at it again.  Jab someone with about 100 uU (/min*kg), and muscle and fat vacuum glucose out of the blood.  Same goes for potassium; and adipose gets all stingy too… it stops releasing and starts storing fat.  This is “healthy,” and its part of why people say insulin, and by extension carbohydrate, causes lean people grow fat tissue.

What do you think would happen in an insulin resistant obese crowd.  Less glucose vacuuming, but scrooge adipose will still responds with gravitas, by saving more and spending less?  Likely.  HSL is like the little piggy’s straw house.  The strong young wolf can blow it down.  The COPD emphysema wolf can blow it down…  because it’s made of straw.

Thus, insulin causes lean people to grow fat tissue, and it causes obese people to grow more fat tissue.

In other words, with regard to common obesity, being resistant to insulin means postprandial hyperglycemia; you can’t handle sugars proper.  but it’ll still make you fat(ter).

Expt 2. The interesting part.  Try jabbing healthy people with 10x less insulin.  Looks like IR obesity!  Adipose gets stingy, potassium scrams, but no effect on glucose uptake.

In the figure below: A-DV is muscle; A-SV is adipose.  Glucose uptake into fat & muscle is unaffected by a low dose of insulin.glucose on 10uU

Second figure: with the same dose, adipose goes on a budget SAVE MORE SPEND LESSFAs on 10 uU

Conclusion.  In a healthy person, (eg, healthy person), even very low doses of insulin cause fat growth.  This isn’t an issue of high vs. low glycemic issue.  The insulin dose used in this study was less than that expected from a respectable low glycemic index meal.  This is probably why the glycemic index hasn’t cured the obesity epidemic.  On the other hand, dietary fat doesn’t stimulate insulin…  just sayin’

Furthermore, perhaps glucose uptake into adipose promotes fat storage under certain conditions, but it’s clearly neither necessary nor essential.  Insulin can Miracle Grow fat mass without affecting glucose uptake one iota.  I imagine the abundance of 3C precursors simply isn’t “the limiting factor.”  And it works just as good with Whole Foods Low GI pa$ta and Wonderbread.buttressed

Translation: insulin buttresses fat growth.  and it doesn’t matter how much.  FYI this probably seems nonsensical at first: carbs stimulate insulin in order to dispose of said carbs, like a logical feedback mechanism.  Perhaps.  But said insulin cares far more about fat than said carbs.  On a scale of 1 to 10 (ie, putting things into “perspective”): insulin is there to grow fat tissue for the obesity epidemic, not replenish glycogen after yoga.



Part II.

Dose-dependent effect of insulin on plasma free fatty acid turnover and oxidation in humans (Bonadonna et al., 1990)

There are a lot of data in this paper, but here are the relevant points:

Infuse insulin at various rates.  In the lowest infusion rate, the only aspect of glucose metabolism to respond is hepatic glucose production (second line; HGP declines from 2.0 to 1.34 at the lowest dose):glc turnover

WRT low dose insulin on glucose metabolism: liver responds, not skeletal muscle.  Skeletal muscle doesn’t even look at glucose until insulin infusion reaches 250 – 500 uU, which is probably why back in ’64 they saw absolutely no effect at 10 uU.  At 100 uU they saw an effect, but according to these data, it was likely due solely to liver, because skeletal muscle doesn’t seem to care until levels exceed 250 uU (it’s an infusion rate, not an absolute concentration.  But that’s neither here nor there).  To be clear, 10 uU insulin infusion doesn’t affect glucose metabolism (1964).  period.  100 uU modestly affects it (1964), and this is probably so modest because only liver is helping out (1990).  At 500 uU, full scale attack on blood glucose.

But fatty acids are obliterated with 5 – 50 x less:FA turnover

It worked with 10 uU in ’64, and it worked just as well with 100 uU in ’90.  (FYI the first paper was published in 1964; this one in 1990).

Furthermore, in the table above glucose metabolism was progressively affected with increasing insulin concentrations.  Not so much with FAs:FA suppression

FA flux is rapidly and completely shut down with a dollop of insulin.  Indeed, it is obliterated.  Giving more insulin doesn’t do anything, because, well, when you blow down a straw house, it tends to stay down.


calories proper


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Biohacking holiday weight gain

What should you eat before the big feast?  (hint: eggs.)  And don’t try to compensate in advance by eating less, this will only make you hungrier.  Furthermore, foods in your regular diet are probably healthier than holiday fare, so you definitely don’t want to eat fewer healthy foods to make room for empty calories.

Tip 1. 

Variation in the effects of three different breakfast meals on subjective satiety and subsequent intake of energy at lunch and evening meal (Fallaize et al., 2012)

Participants were served only one of these for breakfast:

And given unlimited amounts of these for lunch and dinner:

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