Tag Archives: diet

Gut microbiome & short-chain fatty acids: resistant starch vs. prebiotics

Posted on December 30, 2013 | 105 comments

Bifidobacteria undoubtedly like resistant starch (RS).  They bind and hold on tight, an effect mediated by cell surface proteins.  Big thanks to Tim Steele for passing along many of the studies cited here.  One of said studies showed that treatment of bifidobacteria with proteases abolished the RS binding; but even dead critters would bind if their cell surface proteins were intact (Crittenden et al., 2007).  

I suspect fermented foods have this all figured out.  The microbes in sauerkraut are going to be embedded in & all around the cabbage polysaccharides; likely protected from digestive enzymes (to a degree) and holding on tight.

Something similar has been shown for galactooligosaccharides (GOS) (Shoaf et al., 2006).  In this study, GOS, but not a variety of other fibres, inhibited the binding of pathogenic gut microbes to intestinal epithelial cells.

These mechanisms are likely not mutually exclusive, and both seem like they could benefit the host (us).

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Posted in Advanced nutrition, chocolate, diet, Grains, microbiota

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On resistant starch and blood glucose control

Posted on December 20, 2013 | 100 comments

For overall health and well-being, fermented foods like sauerkraut and kefir are great.  Especially when following a low carbohydrate diet which is generally low in the types of foods which feed the gut microbiome.

For those with gastrointestinal problems, the gut microbiota is probably involved.  Whether it is bacterial overgrowth or dysbiosis, gut bugs are usually the culprit.  Treatment options vary widely, ranging from global extermination with vinegar & a low fibre diet (as per Jane Plain), or remodeling the microbiome with a prebiotic like galactooligosaccharides.   Probiotics like bifidobacteria can help, too, if they’re administered with either prebiotics or fermented foods (they need something to nourish them in transit).  Dark chocolate is also an excellent vessel.  Resistant starch is another option, although the question remains as to whether or not this is compatible with a low carbohydrate diet.

Resistant starch has been around for a while, and when I was in school it received about 10 minutes of attention during the fibre lecture.  But Jimmy Moore and Richard Nikolay have been talking about it a lot lately so I decided to freshen up on the topic.  In brief, it can be therapeutic for GI issues, but some studies have shown mixed effects on glucose & insulin metabolism.  The former is virtually unarguable, but I found the latter interesting.  And the impact of resistant starch on ketosis is included as well.

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Posted in Advanced nutrition, clamp, diet, fiber, Grains, insulin, Ketosis

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Dietary protein, ketosis, and appetite control.

Posted on December 6, 2013 | 118 comments

“Dietary protein has a purpose, and that purpose is not carbs.”  Nor is it to break ketosis or stall weight loss.  

Drastically increasing protein intake may reduce the degree of ketosis in the context of a large energy surplus, but this is likely due more specifically to the large energy surplus than the protein.  This would explain why Warrior dieters (1 meal meal per day) often report reduced ketones if they eat too much protein.  It’s more likely that the 2000 kcal bolus is exerting it’s anti-ketotic effect by being a large energy surplus, such that anything other than 90% fat would blunt ketosis.  It’s not the proteins… Want proof?  Here’s an n=1 to try: give up Warrior dieting for a few days and try 3 squares.  My bet is that you’ll be able to increase protein intake and still register ketones as high or higher than before.  There are data to support this and reasons why it may not matter (below).

disclaimer: I don’t think “deep ketosis” is necessary to reap the benefits of carbohydrate-restriction.  But if you love high ketone meter readings, then this might be a better strategy to maintain deep ketosis while getting adequate protein. win-win.

if I hear: “oh no, I was kicked out of ketosis!” one more time… 

All of the studies below are confounded one way or another, but so are we humans.

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

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Implications of the circadian nature of ketones.

Posted on November 24, 2013 | 38 comments

Ketosis.  Happens during starvation and also by restricting carbohydrates (and protein, to a lesser degree)… might be important for epilepsy and bipolar disorder, too.

ketogenesis

Ketostix measure urinary acetoacetate (AcAc) and reflect the degree of ketosis in the blood probably about 2-4 hours ago.  Blood ketone meters measure beta-hydroxybutyrate (bHB) right now.  bHB fluctuates to a greater degree, eg, it plummets after a meal whereas AcAc takes longer to decline.  AcAc/bHB is usually around 1, but increases after a meal (Mori et al., 1990):Ketone body ratio

Conversely, when glucose levels decline and fatty acid oxidation increases, liver redox potential drops which reduces AcAc/bHB.

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Posted in Advanced nutrition, circadian, depression, diet, Dietary fat, epilepsy, Exercise, fat, Ketosis

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Low carbohydrate diets favorably impact testosterone levels.

Posted on November 17, 2013 | 43 comments

It is known.  Carbohydrate restriction improves (lowers) testosterone in women with PCOS.  It works for men, too… but by “works” I mean “increases.”

Decrease of serum total and free testosterone during a low-fat high fibre diet (Hamalainen et al., 1982) 

Intervention pseudo-crossover study: 30 healthy Finnish men in their 40’s were studied on their habitual high fat diet (40%  fat), then put on a low-fat (25%) high fibre diet for 6 weeks, then switched back to high fat.  The high fat diet was also higher in saturates, P:S ratio 0.15 vs. 1.25.

free T

 

Free testosterone levels declined on the low fat diet, but they recovered after 6 weeks of going back to their high [saturated] fat dieting (p < 0.01).

Some observational data: Testosterone and cortisol in relationship to dietary nutrients and resistance exercise (Volek et al., 1997)

…fat, and in particular saturated fat, is associated with increased testosterone levels [in men]:

observational

 

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Posted in Advanced nutrition, clamp, diet, Dietary fat, fertility, insulin, sex, testosterone

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Protein Leverage Hypothesis

Posted on November 10, 2013 | 40 comments

Inverse Carb Leverage HypothesisTM

Protein Leverage Hypothesis: Dude eats 15% protein on a 2000 kcal diet (75 g protein).  Exchange 25 grams of protein with carb, and he’s now eating 10% protein on a 2000 kcal diet (50 g protein).  Theory states Dude will increase total food intake to get back those 25 grams.

Ergo, Protein Leverage Hypothesis:

protein leverage hypothesis

Disclaimer: I don’t care much for the Protein Leverage Hypothesis.  It might be true, but that doesn’t mean it matters.  It works well in rodents, but obese patients eat tons of protein.  The rebuttal to this is that the protein in their diet is too diluted with other [empty] calories.  They’re overeating because of low protein %.

The flipside, confirmed ad nauseam in rodent studies, is that frank protein deficiency increases food intake.  Frank protein deficiency means negative nitrogen balance & tissue loss… not just skeletal muscle; organs, too.  Incompatible with survival.

Feed someone a low protein low fat diet, they get hungry.  If it’s ad libitum, they eat more.

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

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Ketosis: anti-brain fog. Neurotransmitters, dietary protein, and the gut microbiome.

Posted on October 27, 2013 | 51 comments

Treatment for dietary protein-induced brain fog: dark chocolate with 3% GOS and 10% MCTs.  Who’s in?

#IntermediaryMetabolism (bear with me here)
Ketosis from liver’s perspective:  increased fatty acid influx & [partial] oxidation causes acetyl-CoA levels to rise dramatically.  Concomitantly, gluconeogenesis redirects oxaloacetate (OAA) away from combining with acetyl-CoA via TCA cycle citrate synthesis and toward gluconeogenesis.  Since the acetyl-CoA doesn’t have much OAA with which to couple, it does itself to make acetoacetate.  Ergo, ketosis, and fortunately liver lacks ketolytic apparatus.

ketosis

 

Brain is singing a different tune.  Ketones provide ample acetyl-CoA and are efficiently metabolized in the TCA cycle.  Ketolysis is not ketogenesis in reverse, else liver would consume ketones.keto metabolism

Teleologically speaking (and I don’t really know what that word means), ketones are meant to spare glucose for the brain by replacing glucose as a fuel for peripheral tissues like skeletal muscle and displacing some brain glucose utilization.  The former is vital as one of the few sources of “new” glucose is skeletal muscle amino acids, and they would be exhausted in a short amount of time if skeletal muscle kept burning glucose –> incompatible with survival.  Getting some of that fuel from fatty acids, ie, ketones, is just way better.  Thus, the “glucose sparing effect of fat-derived fuel.”  And by “glucose,” I mean “muscle;” and by “fat-derived fuel,” I mean “ketones.”  There are numerous intracellular signaling events and biochemical pathways pwned, but that’s the gist of it.

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Posted in Advanced nutrition, chocolate, coconut, diet, fiber, liver, microbiota, Protein

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Summer is fattening. Don’t do it in winter.

Posted on September 5, 2013 | 32 comments

Seasonal eating proper

More on seasonal eating in what appears to be the primary model for its justification for use in humans – hibernating mammals.

How it goes, or so they say: in summer, hibernators massively overeat, including carb-rich foods, in order to generate muscle and liver insulin resistance, so as to promote body fat growth.  The long light cycle reduces evening melatonin, which pushes back the usual nighttime peak in prolactin, which causes an abnormal resistance to leptin, which induces hypothalamic NPY and subsequent carbohydrate craving.  Ergo, summer is fattening.  In today’s day, increased artificial lights guarantee year-round pseudo-summer; and we no longer experience the benefits of the short light cycle: longer sleep times (akin to hibernation) and fasting – either complete fasting as in hibernation, or pseudo-fasting, ie, a ketogenic diet.

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Posted in Advanced nutrition, Bromocriptine, circadian, diet, Dietary fat, Dopamine, empty calories, Energy balance, fat, Fructose, insulin, Leptin, TPMC

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Nutrition Disinformation III

Posted on August 23, 2013 | 4 comments

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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Posted in Advanced nutrition, diet, empty calories, Energy balance, fat, insulin, Orlistat, TPMC

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Calories schmalories, alcohol, and chocolate

Posted on August 15, 2013 | 50 comments

Some calories count, others don’t.  Some calories work in some people, but not others.  Does this sound like an irrefutable Law of Nature?  No, but it is a perfectly acceptable tenet of the Laws of Energy Balance (a construct of my design).

Do alcohol calories count?  Sometimes, but not this time:

The energy cost of the metabolism of drugs, including ethanol (Pirola & Lieber 1972)

This was a study on bona fide alcoholics who participated because they were promised treatment.  Metabolic ward.  FYI, one gram of alcohol burned in a calorimeter produces ~7.1 kilocalories; alcohol = 7.1 kcal/g.

Calories required to maintain body weight (ie, = total energy expenditure) was assessed the old-fashioned way: feeding them enough calories to maintain a stable body weight – they counted calories but relied on the bathroom scale to establish a baseline.  #TPMC.  After a week of weight stability, they ISOCALORICALLY exchanged carbohydrates for alcohol, and broke CICO.

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

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