Tag Archives: diabetes

LIGHT, Leptin, and Environmental Mismatch

For a long time, the melanocortin system was basically thought to control the color of skin and hair.  It still does, and many redheads are redheaded due to polymorphisms in one of the melanocortin receptors.

Fast forward to 2015: to make a long story short, melanocortins are HUGE players in circadian biology.

 

POMC ACTH a-MSH

 

Brief background (also see figure above):

Fed state -> high leptin -> a-MSH -> MC4R (the receptor for a-MSH) = satiety, energy production, fertility, etc.

Fasted state -> low leptin -> AgRP blocks MC4R = hunger, energy conservation, etc.

MC4R polymorphisms in humans are associated with obesity.  Melanotan II causes skin darkening (marketed as “photoprotection” [no bueno, imo]), enhanced libido, and appetite suppression.

 

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Circadian Disruption Impairs Survival in the Wild

…just read that huge disasters, ranging from Exxon Valdez to Chernobyl, may have been due, in part, to ignorance of basic principles of circadian rhythms.  Gravitas.

 

circadian rhythms

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Carb Back-Loading and the Circadian Regulation of Metabolism

Carb Back-Loading (CBL) redux, part I

Step 1: eat little in the morning (maybe some fat+protein; definitely no carb)
Step 2: exercise in the afternoon/evening
Step 3: eat the carbs, all of them.  Preferably high glycemic carbs.
Other: no dietary fat post-workout; protein periodically throughout the day.

What makes CBL different from its predecessors is the stress on the timing – exercise and carbs in the evening.  John Berardi’s “Massive Eating” dietary guidelines are similar: protein+fat meals all day except pre- and post-workout, which are protein+carb meals.  Martin Berkan’s “LeanGains” is fasting most of the time (including pre-workout), exercise in the afternoon, then a big post-workout meal (quite similar to CBL).  My only tweak, as discussed below (and previously here and here), would be a pre- rather than post-workout meal [in some contexts].

There’s a summary of this blog post at the bottom… it might be helpful to read that first (see: “Tl;dr:”).  Also, please note that much of this post is about the fringe of theoretically optimizing nutrient partitioning, like improving from 85 to 90%, or 40 to 45%, not 40 to 90%…  I’m not that deluded.

My initial take, in general, is that this book is loaded with gems about nutrition, exercise, biochemistry, and physiology.  It’s also very readable and has a lot of good recommendations.  In this post, I want to discuss one specific aspect of CBL: tissue-specific circadian regulation of metabolism.

 

nutrient timing

 

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Lipid Hypothesis 2.0: Eat Butter

The original lipid hypothesis stated, more or less, that lowering blood cholesterol would reduce premature mortality from heart disease.  At the time, it was thought that dietary cholesterol and saturated fat increased the ‘bad’ type of blood cholesterol, so the advice was to restrict those foods.  All of that was wrong.

Time

Lipid Hypothesis 2.0: Eat Butter

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Advanced glycation end products (AGEs)

About a decade ago, Michael Brownlee posited that AGEs were one of The Four Horsemen responsible for the microvascular complications of diabetes.

Kill ‘em all

Thereafter, the image below (or a closely related one) appeared in at least one talk at every major diabetes conference for about 5 years.  Then it faded – maybe not because it is wrong, but rather just too simplistic to be useful (similar to CICO & ELMM).

Brownlee

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Skipping meals, intermittent fasting, grazing, etc.

or… Circadian Meal Timing!

They say if you’re going to [intentionally] skip a meal, it should be breakfast – and hey, that’s probably the easiest meal to skip.  However, a recent study showed skipping dinner FTW (well, not exactly).  I’ve never seen a proper study directly comparing the effects of skipping different meals, but here are a few that come close.  The findings may surprise you.

omelette

note: with the exception of Fernemark (Exhibit B), these studies are mostly macronutrient-controlled. That is, protein, fat, and carbs are similar between the groups; the only thing that differs is when they were ingested.  This can be tricky and/or very nuanced in some instances, like if dinner was smaller (fewer calories) but more protein-rich, for example… but in order to include 5 relevant studies and not bore you to death, you’ll have to check the full texts for those details.

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Nutrition Disinformation III

but they actually get it right this time.   Big HT to George Henderson for bringing this ms to my attention.

In Nutrition Disinformation, Part I, the Mediterranean diets employed by Estruch & colleagues were discussed.  The study subjects’ need for antidiabetic drugs, insulin, and anti-platelets all increased over the course of 5 years.  The media and even the authors themselves reported the opposite, touting the benefits of Mediterranean diets.  Thus begat the Nutrition Disinformation series.

Nutrition Disinformation 2.0 was a follow-up to an older post on the Look AHEAD study, when the results were finally published.  The intensive lifestyle intervention consisted of a pharmaceutical-grade low fat diet (ie, LFD + a little bit of Orlistat), and exercise.  By the end of 10 years, medication use was modestly lower in the intensive lifestyle group compared to controls, but it was markedly increased from baseline.  Therefore, I deemed it egregious to say their intervention was “healthy.”  In the context of Nutrition Disinformation, “healthy” means you’re getting better.  The need for insulin, statins, and anti-hypertensives should decline if you’re getting better.

In part 3 of the series, Yancy must’ve been following the Nutrition Disinformation series :) and decided to conduct a subgroup analysis on the patients in his previous low carb vs. low fat + Orlistat study.  Weight loss was roughly similar, but all other biomarkers improved more on low carb.  In the new publication, Yancy analyzed data selectively from the diabetic patients in his original study to generate a “Medication Effect Score (MES).”  MES is based on what percentage of  the maximum dose was a patient given, and adjusted for the median decline in HbA1c experienced by patients on said drug.  A bit convoluted, but I’m on board (at least tentatively).

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Look AHEAD – Nutrition Disinformation 2.0

The day you’ve all been waiting for has finally arrived.  Results from the Look AHEAD study have been published.  When I first wrote about this study (HERE), it had been prematurely halted because the intervention was providing no benefits.  Everybody was in a state of shock and awe because Low Fat didn’t save lives.  But that was before we even had the data.  

Reminder: the “intensive lifestyle intervention” consisted of a Low Fat Diet & exercise.  The results?  Yes, they lost more weight than control, but they also took more Orlistat (of which I’m not a fan, see HERE for why):

orlistat

Orlistat = pharmaceutically enhanced low fat diet. 

Their normal diets were not healthy, but neither was low fat –>

med use

Medication use increased drastically in both groups.  The pundits have gone wild because medication use was lower in the intensive Low Fat group at the end of the study, but this is Nutrition Disinformation 2.0.  Eerily reminiscent of the recent Mediterranean Diet study, the conclusions are the same: keep eating poorly and the need for medications will increase.  You can call it a lot of things, but not “healthy.”  The alternative –>  How to define a “healthy” diet.  Period.


Significant adverse events:SAE

The only thing to reach statistical significance was more fractures in the intensive Low Fat group, but you didn’t read any headlines that said “Low Fat breaks bones.”  Imagine if that happened on low carb [sigh]  The next closest thing to statistical significance was increased amputations in the intensive Low Fat group :/

gem:History of CVD

Translation: if you were healthy at baseline, then you could tolerate a low fat diet.  Otherwise, not so much.  This is exactly what happened in the Women’s Health Initiative.

Ha

needless to say, none of the “possible explanations” they considered were Low fat diet Fail.

calories proper

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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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The curiosities of nicotin..ic acid

Niacin vs. ketosis

Part I.  Rodents

It is thought: niacin causes red itchy face (> 100 mg/d) and acutely lowers FFAs; chronically, it raises some questionable fraction of HDL (> 1000 mg/d) and probably causes diabetes.

It is speculated: niacin binds a particular “ketone” receptor (GPR109?) (physiological relevance?).

It is known: niacin is ketogenic in rats.  Repeat: niacin is ketogenic in rats.

Niacin aka nicotinic acid and nicotamide aka niacinamide both fulfill the requirement for Vitamin B3 (ie, prevent pellagra).  But only the former causes flushing… and only the former is ketogenic (two apparently unrelated phenomena).

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