Insulin resistance and obesity

Posted on June 25, 2016 | 32 comments

Some people believe insulin resistance (IR) causes obesity, and they are not pleased when I say this is actually a controversial topic in the field…

“Bill isn’t toeing the company line.  Again.”

So I asked a simple question: if IR causes obesity, how?

 

 

The Common Response: 1) IR -> 2) hyperinsulinemia -> 3) more insulin = more fat mass.

However, this is flawed.

Easiest rebuttal (somewhat of a strawman, but whatevs): Barbara Corkey and her group has done a lot of work showing that insulin hypersecretion (caused by dietary additives, preservatives, weird chemicals, etc.) may actually precede & causes IR… not enough insulin hypersecretion to induce hypoglycemia, just enough to induce IR.

So that basically breaks the 1st step in the Common Response, but doesn’t really disprove the possibility that IR still causes obesity (or can cause obesity).

In any case, check out Corkey’s 2011 Banting Lecture.  Highly recommended, a lot of food for thought.

 

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Posted in Advanced nutrition, angiotensin, Bromocriptine, Cabergoline, chronopharmacology, circadian, diabetes, diet, Dietary fat, Dopamine, insulin, Leptin, Protein, TPMC

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Hey CICO, I’m playing by your rules.

Posted on June 15, 2016 | 6 comments

Brief background: the notorious Ebbeling study of 2012 showed an apparent metabolic advantage of a ketogenic diet.  After losing some weight, participants were assigned to low fat (LF), low GI, or ketogenic diets.  As expected, energy expenditure (EE) declined in all groups after weight loss.

 

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Posted in Advanced nutrition, diet, Dietary fat, empty calories, Energy balance, fat, fiber, insulin, Ketosis, microbe, microbiome, microbiota, muscle, TPMC

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Dopamine and breakfast

Posted on June 5, 2016 | 39 comments

T.S. Wiley wrote a lot about the protein-rich breakfast; here’s my understanding of her take on it.

N.B. I highly recommend her book, Lights out: sleep, sugar, and survival.

Quotes are mainly taken from the text. I’ve tracked down some of the cites; the rest are in the back of the book, albeit somewhat unorganized :/

Part 1. We naturally have a cortisol spike first thing in the morning, known as the Cortisol Awakening Response (CAR).  This peak, which can be screwed up by artificial light at night or a big evening dinner, helps support morning light-induced dopamine.

CAR

Dopamine is great, but may induce impulsivity if it’s unfettered.

Enter: the protein-rich breakfast. It provides tryptophan and a bit of insulin to promote serotonin synthesis (eg, Manjarrez-Gutierrez et al., 1999).

Not enough serotonin to make you crazy, just enough to balance the dopamine = impulse control.

~ circadian balance achieved ~

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Posted in Advanced nutrition, angiotensin, Bromocriptine, Cabergoline, chronopharmacology, circadian, diet, Dopamine, fat, Fish, insulin, Leptin, melatonin, Protein, sex, sleep, Sun, TPMC, Vitamin D

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Vasopressin’ me again

Posted on May 25, 2016 | 3 comments

I’ve been following the links between blood pressure modulatory hormones and circadian rhythms for a while now — and while it’s a fascinating overall picture, this nut hasn’t been cracked [yet].  A paper published in Science may have brought us one step closer.  (And some potential biohacks.)

Background reading (probably important, because my thoughts on this aren’t very coherent [yet]):

LIGHT, Leptin, and Environmental Mismatch (skip down to Part 2)

Circadian phase delays and metabolism

Circadian biology: jet lag, mood, & potential role of BP regulatory peptides

 

The new study: Changes in the composition of brain interstitial ions control the sleep-wake cycle (Ding et al., 2016)

It was a study on mouse brain, but the #context is very relevant here.

Tl;dr: they showed that changes in extracellular ions, independent from neuronal activity, can induce sleep or wakefulness.  “Independent from neuronal activity” was accomplished by silencing the neurons with tetrodotoxin.

 

Pufferfish

 

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Posted in Advanced nutrition, Bromocriptine, Cabergoline, chronopharmacology, circadian, Dopamine, Leptin, melatonin, Sun

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the insulin-obesity hypothesis is under attack

Posted on May 15, 2016 | 25 comments

…but it isn’t dead, imo, because that would be really hard to do.  Like, seriously.

 

 

side note: please consider the modern views of Taubes, Lustig, Gardner, Attia, and others on Carbs™.  They’re less “Carbs-cause-obesity, keto-for-all, etc.,” and more thinking it might not be Carbs™ per se, but rather processed and refined foods.  And #context…  And I tend to agree at the moment (nuances and caveats are subject to change, as more evidence accumulates).

 

disclaimer: I haven’t seen the full text of Hall’s recent study, but that’s not really relevant to what I want to discuss.  In other words, I don’t think the full text will provide any additional details on this particular point.

 




 

Tl;dr: this study was not designed to prove or disprove metabolic advantage or the insulin-obesity hypothesis.

It’s in the study design:  four weeks of low fat followed by four weeks of low carb.  We KNOW that weight loss slows over time (especially if calories are controlled, as they were in this study).  It has to do with the order of treatments.

Weight loss-slowing over time in the Minnesota Experiment:

 

 

Minn-Starvation-weight

 

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Posted in Advanced nutrition, diabetes, diet, Dietary fat, empty calories, Grains, insulin, Ketosis, Leptin, Protein, sleep, Sun, TPMC

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Social jet lag

Posted on May 5, 2016 | 4 comments

Social jet lag is basically a general term that refers to circadian arrhythmia.  Sort of like insulin resistance, it’s rampantly abundant — some have estimated a prevalence of up to 75%!  Social jet lag can be induced by shift work, East/West travel, late meal timing, artificial light at night, sleeping late, not enough sunlight in the morning, etc., etc.  And while any of the above insults, by themselves, may not really screw up your circadian rhythms, you can see how easy it is for one person to fall prey to nearly of them:

Eat a late dinner, stay up late using artificial light (eg, computer, smart phone, etc.), sleep late the following day so you skip breakfast and don’t get any sunlight in the morning.

CIRCADIAN MISMATCH ACCOMPLISHED

This increases your risk for a wide variety of ailments, ranging from cancer to diabetes to bipolar disorder: no bueno.

One key mediator of the effects of LIGHT is melatonin.  Artificial light at night suppresses melatonin.  Sunlight in the morning can blunt the impact of this!  It all ties in together.  Gravitas.

Great review article here.

 

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Posted in Advanced nutrition, angiotensin, Bromocriptine, Cabergoline, chronopharmacology, circadian, diabetes, diet, Dopamine, Energy balance, Ketosis, Leptin, melatonin, resveratrol, Sun

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Insulin resistance is a spectrum

Posted on April 25, 2016 | 43 comments

The history of low fat diets is riddled with crappy low fat food-like products.

Food quality matters.

Free full article on Patreon! <- link

Take a group of obese people and assess insulin sensitivity however you like: some researchers demand nothing less than a hyperinsulinemic-euglycemic clamp (Gold Standard), others are OK with insulin levels during an oral glucose tolerance test.

Next, divide the people up based on this — there are a few ways you can do it.  You can: take the top half vs. the bottom half (a method which includes everyone); take the top third vs. bottom third (excluding the middle third); take the top quarter vs. bottom quarter (excluding the middle 50%), etc.

THIS MATTERS because in referencing this topic, many people claim most obese are insulin resistant.  They may be more insulin resistant than lean people, but even within obese people, there’s a spectrum, and the spectrum matters in this #context.

 

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

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Melatonin sensitizes the system

Posted on April 15, 2016 | 12 comments

Bear with me here… this could be very important (or just all in my imagination haha)

Fact: melatonin secretion happens at night (or at least that’s when it’s supposed to happen):

circadian melatonin

And it’s important to adopt healthy circadian behaviors early on to prevent or minimize the age-related decline in melatonin secretion:

melatonin in aging

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Posted in Advanced nutrition, chronopharmacology, circadian, Dopamine, Leptin, melatonin, muscle, sleep, TPMC

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Rodent keto studies

Posted on April 5, 2016 | 9 comments

Next time someone says VLC/keto is harmful or at least not helpful for fat loss because of a new rodent study, they’ll probably be wrong.

BOOKMARK THIS ONE GUYS.

Rodent studies on ketogenic diets or exogenous ketones are valuable and interesting in a variety of #contexts, although I’d argue that regulation of fat mass isn’t really one of ’em.

For starters, rodents aren’t particularly ketogenic – it’s rare to see ketones >1 after an overnight fast even in long-term ketoadapted mice.  Also, many rodents gain weight until they die, whereas humans plateau and stay relatively weight-stable for their entire lives (at least historically, and I’m not talking about yo-yo dieting).

Skeletal muscle, on the other hand, seems more similarly regulated: keto isn’t muscle-sparing in either specie… most people, perhaps unwittingly, increase protein intake on keto, and THIS spares muscle (N.B. this is simply to spare muscle, whereas in non-keto dieters, it’s not uncommon to see increased muscle in the #context of high protein).  That’s because carbs are more anabolic than fat.  QED.

There’s just a fundamental difference in the way fat mass and appetite is regulated between the species.  There are many similarities, which is why these studies are still valuable, but fat mass isn’t one of ‘em.

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Posted in Advanced nutrition, diet, Dietary fat, Energy balance, fat, insulin, Ketosis, muscle, pair-feeding, Protein, TPMC

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Chris Gardner strikes again!

Posted on March 25, 2016 | 154 comments

Weight loss on low-fat vs. low-carbohydrate diets by insulin resistance status among overweight and obese adults: a randomized pilot trial (Gardner et al., 2015)

 

diet compositions

 

Low carb diet: participants went from 230 grams/d to less than 50 for the first 3 months, then creeped up to ~80 over the next 3 months.

Will the critics say “the carbz weren’t low enough!”?  REALLY?

 

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154 Comments

Posted in diet, Dietary fat, Energy balance, fat, insulin, Protein, TPMC

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