Category Archives: insulin

Tissue-specific fatty acid oxidation

Posted on February 19, 2016 | 17 comments

Does it matter where fatty acids are oxidized, liver or skeletal muscle?  Of course, they’re oxidized in both tissues (quantitatively much more in the latter), but relative increases in one or the other show interesting effects on appetite and the regulation of fat mass [in rodents].

Warning: a lot of speculation in this post.

A LOT.

It’s known that LC diets induce a spontaneous decline in appetite in obese insulin resistant patients.  Precisely HOW this happens isn’t exactly known:  the Taubes model?  improved leptin signaling?  probably a little bit of both, other mechanisms, and possibly this one:

 

Exhibit A. Oxfenicine

 

oxfenicine

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Posted in coconut, diet, Dietary fat, Energy balance, insulin, Ketosis, Leptin, liver, muscle, TPMC

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Muscle growth sans carbs

Posted on February 4, 2016 | 38 comments

1.  net muscle growth = synthesis – breakdown

2.  need =/= optimization

3.  #context

 

muscle sans carbs

 

I’m totally cool with keto, honestly!  but still don’t really like seeing stuff like the above graphic and people interpreting it to mean “KETO IS MUSCLE-SPARING.”

 

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38 Comments

Posted in Advanced nutrition, circadian, diet, Dietary fat, fat, insulin, Ketosis, muscle, Protein, sleep

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New low carb protein bars

Posted on January 4, 2016 | 42 comments

Warning: this post isn’t #Paleo Certified™.   It’s more about convenience, choosing the lesser evil.

Quest Nutrition led the charge in low carb, high protein, fibre-rich bars.  “Fibre-rich” is really the key in allowing a bona fide “low carb” bar with shelf-stability and decent texture.  Sugar alcohols have also been used in some, but due to the high incidence of maltitol-induced GI discomfort, ymmv.  But in general, you need one or the other to provide bulk and keep it together (except Epic Bars, which use black magic).

For the most part, the new bars have basically copied Quest’s formula with some new flavors.

 

Disclaimer #1: I’m a whole foods guy.  Not really #Paleo™, but when it comes to people’s actual lifestyles, I recognize convenience is a huge factor… and selecting the lesser evil is frequently the best option — eg, you can store a couple LC protein bars in your office, car, etc.; not so much with hard-boiled eggs or other protein-rich foods… and these options are WAY better than many other snacks or “fast-foods” out there.

Disclaimer #2: yeah, I keep a few of these bars in my office, just in case…

Quest recently switched from isomaltosaccharides to soluble corn fibre (SCF), which will likely impact GI effects.  YMMV!  Isomaltosaccharides are cool, but I’m not prepared to say they’re superior to SCF for everyone, in every #context (personally, for the ‘biome, I prefer brassicas, alliums, the gristly bits, galactooligosaccharides, et al.).
[it’d awesome if Bi2Muno would collaborate with one of these companies]

 

In these n00bs to the protein bar market, some of the biggest differentiating factors are cost, net carbs, ratio of fibre to sugar alcohols, flavor profiles, etc.

 

With no further ado, here are the newcomers:

[or just skip to the chart at the bottom]

 

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Posted in Advanced nutrition, diet, fiber, insulin, Ketosis, microbiome, microbiota, muscle, Protein

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Personalized Nutrition II

Posted on December 13, 2015 | 21 comments

More on Zeevi et al. (2015) (this is a follow-up to part 1)

I like this study a lot, or at least the fundamentals… or new tools that it might bring to the table.  Like, we know sleep and physical activity are important, and we know all calories aren’t created equal.  This study is the next level, showing there are even big differences in specific carb-rich foods depending on who’s eating them.

And more interestingly, if I’m interpreting the results of the intervention study correctly (which may not be the case), gut microbial responses to specific foods were very individualized… and predictable!

But first, the main part of the study — standardized meals (after overnight fast): 50g carbs from glucose, white bread, bread and butter, bread and dark chocolate, and fructose.  All repeated at least once (except fructose).  Everyone responded pretty similarly to fructose (little to no blood glucose spike), but a wide range of responses to glucose.

PPGR = PostPrandial Glucose Response

 

glucose and fructose

 

Bread:

 

bread

 

The range of PPGR to bread was ~15 to 79!

Again, here are some of the findings I found most interesting (besides the huge range in glycemic response to bread):

 

 

banana and cookie

 

Participant #468 has a consistently higher response to glucose than to white bread.  Participant #663 is the opposite.  And participant #445 is still winning.

I truly wonder if there’s a gut microbe (or something) that’s involved here…

 

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21 Comments

Posted in Advanced nutrition, chocolate, diet, Dietary fat, insulin, Leptin, microbe, microbiome, microbiota, Protein

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Personalized Nutrition by Prediction of Glycemic Responses

Posted on November 27, 2015 | 53 comments

“please stop asking gurus how many carbs you need to optimize health”

 

bananas cookies

An interesting paper came out recently by Zeevi et al. (2015), showing, in part, that we’re all unique snowflakes (in some contexts).

 

#context

#context

 

Mini-rant: this study is in line with a lot of my beliefs about individuality in human biology.  We don’t know all the mechanisms, but we do know that some people respond better to some interventions than others.  We learn a lot from studies on diet, light, sleep, physical activity, etc., but the findings rarely/never apply equally to everyone (and some people experience completely opposite effects; eg, see studies where individual data are reported).  LIGHT exposure can improve sleep quality in some but cause agitation in others.  Low carb diets can help weight loss in some people but low fat is better for others.  Dairy, wheat, protein, the ‘biome, and fibre/resistant starch all fall into this category.  Sleep ‘requirements’ vary by person, season, geography, etc., etc…  there’s no QED answers in many of these contexts.

anecdote: some people say they’ve never had better blood glucose than when they were having a few servings of beans/legumes per week; others just report bloating & farts (no bueno).

End rant.

Background reading:

  1. The Atlantic ran a decent piece on this study (certainly more colorful than my take)
  2. Reddit AMA with some of the people involved in the study

 

In this particular study (video summary below): they continuously monitored the blood glucose responses in 800 people to all of their meals for a week, including a variety of test meals.  Main result: many different responses, even to the same foods!  An oversimplified example: some people had smaller relative postprandial glucose excursions after 50g carbohydrate from rice compared to 50g carb from potatoes, and other people responded oppositely.  And friggin’ tomatoes?!

Translation: need to move beyond recommending #IIFYM.

Some foods were universally well-tolerated [in this population] in the context of mixed meals, like quinoa and salmon; other foods did the opposite, like chocolate chip cookies and sushi.  And lastly, some foods like cottage cheese and hummus were good for some people but others.

 

bananas cookies[participant 445 is winning]

 

*In general, I don’t believe in labeling foods as categorically good or bad, which is pretty much confirmed by this study, but some patterns emerged wrt postprandial glucose excursions in this population…

#context

 

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53 Comments

Posted in Advanced nutrition, diabetes, diet, Dietary fat, fat, insulin, Leptin, microbiome, microbiota, Protein

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HANGRY!

Posted on November 15, 2015 | 50 comments

So the theory goes: high carb meal -> blood glucose spike -> insulin spikes a little too hard -> hypoglycemia -> hunger, so you eat to replenish blood glucose.

In the original theory of hangry, hypoglycemia was a core component, although as Jane Plain pointed out, it could be the relative, not absolute levels of blood glucose that count (&/or free fatty acids, but that’s a story for another day).  This could be true, in part because:
1) symptoms of hypoglycemia rarely correlate with actual hypoglycemia;
2) many episodes of actual hypoglycemia are asymptomatic; and
3) hunger isn’t even one of the main symptoms of hypoglycemia.

 

Tl;dr: hangry might be a real phenomenon, but there are little/no data to support it, and much to the contrary.

 

The low carb brigade says “LCHF = no hangry.”
Turns out, the same can be said by the high carb brigade (in some contexts), so does it really matter? (see below)

 

What we know: obese insulin resistant patients undergo a spontaneous reduction in appetite upon initiating a carbohydrate-restricted diet.  FACT (P<0.05).  Low carb, high protein meals also induce more satiety than high carb meals in acute scenarios…

Imho, hunger and satiety are complicated biological phenomena that can’t be so easily simplified into cute concepts like “hangry.”

 

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50 Comments

Posted in Advanced nutrition, diet, empty calories, Energy balance, insulin, Protein

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The “Insulin Index”

Posted on October 14, 2015 | 58 comments

Similar to the glycemic index, which is an estimate of the rise in blood glucose after eating a particular food, the insulin index is an estimate of the rise in insulin after eating a particular food.  In general, these indices are obvious: processed carbs have high glycemic and insulin indices, whereas whole foods are lower.  Some exceptions are things like dairy and lean meat, which induce more insulin than you’d expect given to their low carbohydrate content…

STORY TIME

When some protein-rich foods were discovered to induce insulin secretion, people thought this information might help type 1 diabetics more accurately calculate their insulin dose.  Interesting rationale, worth testing.

Tl;dr: it didn’t work very well.

More of the protein-derived amino acids may have been incorporated into lean tissue, but the extra insulin load ended up causing hypoglycemia more often than not.  Hypoglycemia is acutely more harmful than hyperglycemia, and is still quite harmful in the long-term.  Some studies on incorporating the insulin index for type 1 diabetics are mixed, ie, increased or no change in risk of hypoglycemia, but no studies show it reduces the risk.

 

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Posted in Advanced nutrition, diabetes, diet, Dietary fat, Energy balance, fat, insulin, Ketosis, Leptin, muscle, Protein

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“Insulin Dynamics”

Posted on September 28, 2015 | 33 comments

This one has a bit for everyone.

 

Relationship of Insulin Dynamics to Body Composition and Resting Energy Expenditure Following Weight Loss (Hron et al., 2015)

 

I think study was actually done a few years ago, originally published here (blogged about here), and re-analyzed through the eyes of Chris Gardner.  I think. (But it doesn’t really matter as the study design appears to be identical.)

 

Experiment: give someone an oral glucose tolerance test (75 grams glucose) and measure insulin 30 minutes later.  Some people secrete more insulin than others (a marker of insulin resistance); these people also have a lower metabolic rate after weight loss = increased propensity for weight regain.  However, if these people follow a low carbohydrate diet, then the reduction in metabolic rate is attenuated.  Some people who don’t secrete a lot of insulin after a glucose load may do better in the long-run with a lower fat diet.

 

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Posted in Advanced nutrition, circadian, diabetes, diet, fat, insulin, Ketosis, Leptin, Protein, sleep, TPMC

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Some nuances of Intermittent Fasting

Posted on September 8, 2015 | 50 comments

Intermittent fasting (IF) is not a universal panacea, regardless of whether you’re not eating anything at all for a few days each week/month or just restricting your feeding window to a few hours per day.

Some protocols, eg, 20h fasting every second day, significantly improve insulin sensitivity in adipose tissue (Halberg et al., 2005). This is expected to make fat gain easier, and while this wasn’t meant to be a study on body composition per se…

 

body composition

 

After just a few weeks, things weren’t changing in a good way (NS).

 

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Posted in Advanced nutrition, chronopharmacology, circadian, diabetes, Energy balance, fat, insulin, melatonin, muscle, sleep, Sun

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Hall et al., THE FIRST SIX DAYS (update)

Posted on August 22, 2015 | 38 comments

Some people say the study design was rigged to favor the Low Fat diet (LF), which is dirty business but not exactly criminal; sometimes, this happens in science.

The claims go something like this: baseline diet was so high in carbs that they were locked into making unreasonable adjustments to formulate isocaloric low fat and low carb diets; eg, fat was too low in the low fat diet and carbs weren’t low enough in the low carb diet.

The biggest finding was “Fat Imbalance,” which favored LF.  Here’s why I don’t think the baseline diet mattered very much.

Tl;dr: drastically cutting fat intake (LF diet) is much more effective than upregulating fat oxidation (LC diet) to create a large Fat Imbalance in an acute setting, ie, THE FIRST SIX DAYS.

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

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