Tag Archives: carbs

Saturated fat, cholesterol, and carbohydrates

“You catch more flies with honey…”

^^^good policy in general, but especially for debating in the realm of nutritional sciences.

 

A short while back, Nina Teicholz discussed low carb ketogenic diets and plant-based diets with John Mackey.  Although I disagree with the dichotomy (keto vs. plant-based), it’s well-worth a watch:

 

 

Three topics that could not be avoided in such a discussion: saturated fat, cholesterol, and carbohydrates.

 

 

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Artificial light regulates fat mass: no bueno.

“despite not eating more or moving less”

We’ve seen this time and time again: LIGHT IS A DRUG.

 

above quote is extrapolated from this rodent study: “Prolonged daily light exposure increases body fat mass through attenuation of brown adipose tissue activity.”

 

Artificial light impacts nearly every biological system, and it doesn’t even take very much to have an appreciable effect (think: checking your smart phone or watching a television show on your iPad in bed at night).  In this study, adding 4 hours to the usual 12 hours of light slammed the autonomic nervous system, disrupting sympathetic input into brown adipose leading to a significant increase in body fat  “despite not eating more or moving less.”

 

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Meal frequency, intermittent fasting, and dietary protein

Dietary protein “requirements” are some of the most context-dependent nutrient levels to decipher, and depend largely on energy balance and even meal frequency.

An objective look at intermittent fasting (Alan Aragon, 2007)

Meal frequency and energy balance (Lyle McDonald, 2008)

New study: “Increased meal frequency attenuates fat-free mass losses and some markers of health status with a portion-controlled weight loss diet” (Alencar et al., 2015)

This wasn’t well-received in social media because bro-science & many low carb advocates say grazing is no longer in vogue — “it’s much better/healthier/whatever to eat once or twice daily, because intermittent fasting and all that jazz” …however, this may be problematic when it comes to meeting overall protein needs, which is particularly important when you’re losing weight.

 

 

The study: 2 vs. 6 meals per day, crossover.  

Conclusion: “On average, fat-free mass (FFM) decreased by -3.3% following the 2 meals/d condition and, on average, and increased by 1.2% following the 6 meals/d condition (P<.05).”  

 

fat-free mass

 

In other words, 6 meals per day was better for body composition than 2 meals per day.  But context is everything, and this hypothesis has been tested from a variety of different angles, so what does it mean?  

The relevant context here: 1) big energy deficit (1200 kcal/d for obese women is a pretty low calorie intake); and 2) “adequateTM” protein intake (75 g/d).

The standard dogma says that in the context of an adequate protein hypocaloric diet, meal frequency matters a LOT, whereas with high protein, it doesn’t matter as much.  Theory being that with an “adequate” (read: too low?) overall protein intake, the fasting periods are simply too long with only two meals per day; you need either: 1) higher protein intake; 2) increased meal frequency; or 3) more calories (ie, smaller energy deficit).  

In this study, BOTH diets suppressed insulin and induced weight loss, but the increased protein feeding frequency skewed the weight loss to body fat while preserving fat-free mass.   I actually agree with a lot of the bro-science in this case, and also think that 75 grams of protein is not enough in the context of a big energy deficit (if body composition is a goal).    




 

Historical precedence?

 

Meal frequency and weight reduction of young women (Finkelstein et al., 1971)

Relevant context:  6 vs. 3 meals per day (3 meals per day may not seem like that many more than 2, but it significantly cuts down on the duration of time spent with no food or protein).

Smaller energy deficit: 1700 kcal/d in overweight patients is less of a deficit than 1200 kcal/d in obese patients.

Higher protein intake: 106 – 115g/d.

Result: nitrogen balance (a surrogate for the maintenance of muscle mass) and fat loss were similar in both groups.  This study fixed two problems in the abovementioned study: 1) 3 meals is better than 2 in the context of an energy deficit; and 2) protein intake was higher.

 

And again here, with 3 vs. 6 meals per day (Cameron et al., 2010), just to make the point that 3 meals per day is better than 2 for preserving lean mass in the context of an energy deficit.

 

The effect of meal frequency and protein concentration on the composition of the weight lost by obese subjects (Garrow et al., 1981)

This study tested the opposite extremes: super-low calorie intake (800 kcal/d), much lower protein intakes (20g – 30g/d), and 1 vs. 5 meals per day.

Result: “a diet with a high-protein concentration, fed as frequent small meals, is associated with better preservation of lean tissue than an isoenergetic diet with lower-protein concentration fed as fewer meals.”

It basically confirmed all of the above.

 

Protein feeding pattern does not affect protein retention in young women (Arnal et al., 2000)

1 vs. 4 meals per day; and 70 grams of protein but no energy deficit (~2000 kcal/d isn’t very hypocaloric for lean young women).  In this study, no effect of meal frequency was seen, likely because 70 grams of protein isn’t inadequate when energy intake isn’t restricted.

 

 

 

1. PROTEIN “NEEDS” ARE HIGHLY CONTEXT-DEPENDENT

2. NEED =/= OPTIMIZATION

3. MEAL FREQUENCY & meal timing and peripheral circadian clocks > “MACRONUTRIENTS”

 

If you’re losing weight (ie, in an energy deficit), then intermittent fasting is cool if protein intake is high (above “adequateTM“)… the bigger the energy deficit, the more protein is necessary to optimize changes in body composition.

 

How much is ‘enough?’  Sorry, can’t give you a gram or even gram per pound of body weight answer… but if you’re losing weight and seeing no discernible effect on body composition (muscle vs. fat mass), then it may be prudent to consider eating more protein-rich foods… and paying more attention to sleep quality (which also greatly impacts nutrient partitioning).

No amount of protein will help you if circadian rhythms aren’t intact!!!

 

 

further reading:

Yes, it’s a high protein diet (Tom Naughton, 2015)

Protein requirements, carbs, and nutrient partitioning

Dietary protein, ketosis, and appetite control 

 

 

calories proper

 

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Non-celiac gluten sensitivity

Gluten is protein, not carbs.  A gluten-free diet is frequently low-carb, because most dietary gluten comes in the form of bread (and wheaty foods).  But believe it or not, bread is an incredibly complex food… many different proteins, carbohydrates, and nutrients that could be problematic for some people (more on this later).

Gluten is not a FODMAP, but most gluten-containing foods are.  Gluten is actually very rich in the amino acid glutamine.  Gluten, not bread.

So we have three studies on purified “gluten,” asking if it’s the gluten, FODMAPs, or something else in wheaty food that is problematic.

Study #1. No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of FODMAPs (Biesiekierski et al., 2013)

Strong study design; patient population was people who thought they were gluten sensitive (but definitely not celiac).

This is the study which led journalists to claim non-celiac gluten sensitivity doesn’t exist, and it’s really sensitivity to FODMAPs, in part, because of this:

 

 

low FODMAPs and gluten free

 

 

Baseline = low gluten diet
Run-in = low gluten and low FODMAPs

 

Here’s the fly in the ointment:

 

symptoms returned in all participants

 

After the run-in period, subjects still followed their gluten-free diets but also received either 16g relatively pure gluten/d (High gluten), 2g gluten + 14g whey protein (Low gluten), or 16g whey protein (placebo).  GI symptoms returned in all participants.  So, low FODMAPs worked for about a week, but then symptoms returned regardless of whether they were eating gluten or not.  In other words, neither low FODMAPs nor low/no gluten worked very well in this study.

But this study may have introduced a brilliant new confounder: food intake was strictly controlled — the experimental diets were different from their normal diets.  Restricting gluten and FODMAPs may have provided some transient benefit, but if the new experimental diet introduced something else that caused problems, then that may explain the gradual return of symptoms…

bollixed?

 

 

Study #2. Small Amounts of Gluten in Subjects with Suspected Nonceliac Gluten Sensitivity: a Randomized, Double-Blind, Placebo-Controlled, Cross-Over Trial (Di Sabatino et al., 2015)

It was another high quality study design: “Randomized, Double-Blind, Placebo-Controlled, Cross-Over.”  And it was addressing a basic question: do people who strongly suspect they have non-celiac gluten sensitivity (NCGS) really have NCGS?  Alternatively, is NCGS real?

Intervention was strong:

1) 4.375 grams of gluten or placebo (rice starch) daily for a week.  This is roughly equivalent to two slices of bread (note: this is way more than enough gluten to destroy the intestines of a patient with bona fide celiac disease).

2) important: they defined the what they would classify as NCGS prior to starting the trial.  A priori.

61 patients strongly suspected of NCGS started the trial, and one withdrew due to gluten-related symptoms in both the gluten and placebo groups.

 

Results:  regardless of whether they were assigned to gluten or placebo FIRST (prior to the crossover), most patients reported gluten-related symptoms.  More importantly, 3 of the 59 patients exhibited significantly worse symptoms on gluten relative to placebo according to the endpoint they defined prior starting the trial.  In one sense, this could be interpreted to mean 5% of people who strongly believe they have NCGS actually have NCGS.

 

gluten sensitive patients

 

Two patients reacted just as selectively strongly to the placebo as the three “real” NCGS patients did to gluten.  Rice-starch sensitivity?

 

See here for a more detailed description of the statistics involved in this study.  I’m willing to accept the “5%” rate, despite the strength of the placebo-responders, whereas the author of that blog post is not.  That’s fair, imo.

And here is another article which questions the legitimacy of NCGS based on this study.  I don’t think that’s totally fair.

And Raphael’s post, where he humorously concludes: “[Gluten-free] does not include advice to sport a gas mask when walking past bakeries.”

 

 

Study #3. Effect of gliadin on permeability of intestinal biopsy explants from celiac disease patients and patients with non-celiac gluten sensitivity (Hollon et al., 2015)

 

 

gluten increases intestinal permeability

 

 

“Delta TEER” is basically the amount of intestinal permeability in intestinal explants exposed to media + gluten (experimental condition) minus those exposed to plain media (control condition).  A better control condition, imo, would’ve been something like they did above: substitute gluten with another protein like whey protein.

 

NC: healthy people
RCD: celiac patients in remission
ACD: celiac patients with active disease
GS: non-celiac gluten sensitivity

 

Active celiac samples responded significantly worse than those in remission, which is good as it functions as a positive control for the experimental protocol.

 

However, gluten sensitive samples responded significantly worse than celiac remission samples; actually, they responded just as badly as celiac samples with active disease.  Celiac disease is supposed to be a million times worse than non-celiac gluten sensitivity… and statistically speaking, even permeability the normal samples declined as much as NCGS samples.

 

This led some to conclude that gluten is bad for EVERYONE.  I’d say it means the assay is bollixed.  Occam’s razor?

 

 

My advice: don’t be anti-science, but don’t use bad science to justify diet choices.  We simply need better studies on non-celiac gluten sensitivity and FODMAPs.

If bread doesn’t work for you, don’t eat bread.  You’re not missing much.

 

calories proper

 

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Carbs: Low vs. Lower

 

 

This was met with much backlash from the low carb cavalry, because, well, if low is good then lower must be better

I’m not anti-keto; but I’m not anti-science.  FACT.  

 

“…some people are not genetically equipped to thrive in prolonged nutritional ketosis.” –Peter Attia

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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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Mushrooms are awesome (P<0.05)

“Without leaves, without buds, without flowers;
Yet they form fruit.
As a Food, as a tonic, as a medicine;
The entire creation is precious.”

-weird mushroom poem of sketchy origin

 

Mushrooms: They have B12! When exposed to UV light, they make vitamin D2.  Protein, fibre, and selenium.  Shall I go on?

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OmniCarb

Why Low Carb?

OmniCarb (Sacks et al., 2014)

Study design & results in a nutshell:

5 weeks, low(ish) vs. high carb (40 vs. 58%) with the calorie difference split between protein (23 vs. 16%) and fat (37 vs. 27%).  In other words, the low(ish) carb diet was higher in protein and fat.  And there was 2 versions of each diet —  a high and low glycemic index.  Lots of crossing over; all in all, weak intervention but decent study design & execution.

Aaaand nothing drastic happened.  Goal was insulin sensitivity, not weight loss.

 

glucose and insulin

 

Important points:

1) The participants were relatively healthy at baseline.  Anyone on meds was excluded.  Average BMI 32.  Mostly educated non-smokers.  This population is expected to respond reasonably well to any diet (wrt body weight… see next point).

2) “Calorie intake was adjusted to maintain initial body weight.”

^^^this really knocks the wind out of low carb. One of the big benefits of cutting carbs is spontaneous appetite suppression –- two points here: 1) this effect is most prominent in obese IR; and 2) it is more relevant to weight loss.  By not targeting insulin resistant and/or type 2 diabetics, and feeding specifically to prevent weight loss, I ask you this: Why Low Carb?

3) the biggest difference between the two diets was carbs (45% higher in low[ish] fat group), but the biggest difference from baseline, was protein in the LC group (53% increase).  In other words, the Low Carb group had their carbs decreased from 50 to 40% of calories. *meh*

4) Body composition wasn’t assessed; so even if LCHP induced nutrient partitioning and improved body comp, we wouldn’t know it.

5) Everyone was eating cereal or oatmeal for breakfast, bread with most meals, and pasta or rice for dinner.  What did you expect?  Really?

REALLY?

Prior posts in what seems to be developing into a series of rants:
2 New Diet Studies
CICO and rant 

 

calories proper

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Circadian phase: role of diet

Circadian phase advance: going to bed earlier, waking up earlier.  Blue blockers at sunset, bright light at sunrise.  Flying east.  Autumn.

Circadian phase delay: staying up late, sleeping in.  Flying west.  Spring.  Using smart phones, tablets, and iPads in bed at night.  Light pollution.

Relative to adolescents, infants and children are circadian phase advanced.  This is part of what is fueling the movement to delay high school start times.  Kids are mentally better prepared to work later in the day.  With early school start times, performance is down in the morning, but they kill it on video games after school.  Delaying start time by an hour won’t totally fix this, but could help.

Edit: it seems like a similar movement is happening for adults, too – ie, starting work an hour later.

I’m not saying everything healthwise deteriorates with age, but the gradual circadian phase delay that occurs with aging and overusing blue light-emitting devices at night might not be a good thing.  If a particular diet can promote phase advance, why not? (at least it’d be countering the phase delay).

 

 

Possible role of diet

In the top half of the figure below, it’s mice fed a “normal diet (ND) (high carbohydrate)” (Oishi et al., 2012).  During normal “light dark (LD)” conditions, movement and feeding is concentrated in the active phase.  When the lights are permanently turned off in “dark dark (DD)” conditions, the free-running circadian clock begins to shift slightly forward (phase advance), but nothing drastic.

 

Phase advance high protein diet

 

In the bottom half of the figure, during normal LD conditions the mice are switched to a low carb, high protein diet.  Note how activity shifts leftward (phase advance) during the LD condition.  When low carb, high protein-fed mice are then switched to DD, we can see a clear circadian phase advance.

 

High protein metabolism

 

Low carb, high protein-fed mice ate more but didn’t get fat; physical activity and body temperature were unchanged.  But this post isn’t about that.  Gene expression of key circadian transcription factors in liver and kidney exhibited phase advances.

The next figure is study to the one above, although instead of switching to a low carb, high protein diet, the mice were switched to a low carb, high fat diet (Oishi et al., 2009).

Note the similarity of control (high carb diet) mice: gradual phase advance when switched to DD:

 

Ketogenic circadian phase

 

The phase advance is markedly enhanced in low carb, high fat-fed mice.

The circadian regulation of activity is similarly affected by low carb, high protein, and low carb, high fat diets.  What do those two diets have in common?

A bit of a stretch? carbohydrate restriction mimics some aspects of avoiding artificial light at night and being young: phase advance.  Whether the carbs are replaced with protein or fat doesn’t seem to matter in this aspect.

 

Wanna know what else can do this?  FOOD.  The food-entrainable oscillator (FEO) kickstarts circadian rhythms.  Rodent studies have shown that timed feeding, regardless of the actual time, consistently realigns the circadian expression of numerous genes (eg, Polidarova et al., 2011 and Sherman et al., 2012).

So what’s the hack?  Food: do more of it, earlier in the day.  Phase advance.  Kind of like avoiding artificial light at night or being young.

 

Oh, and mice exposed to dim light at night (who are pretty much metabolically screwed)? phase DELAYED (Fonken et al., 2010).

 

Dim light at night phase delay

 

 

 

calories proper

 

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CICO and rant

“Wait… what?  nutrient partitioning?”

Calories In, Calories Out should not be interpreted as “eat less, move more,” but rather kept in its more meaningless form of: “if you eat less than you expend, you’ll lose weight.”  At least then, it’s correct… meaningless, but correct.  Eating less and moving more is no guarantee of fat loss, in part, because total energy expenditure isn’t constant and there’s that whole thing with nutrient partitioning.

For obese insulin resistant folks, this is Low Carb’s strong suit: it causes “eat less, move more”spontaneously.

For some obese insulin sensitive patients, for whatever reason, their adherence and success is greater with Low Fat.  You might say, “yeah, but those suckers had to count calories.”  To that, I’d counter with: “it doesn’t matter, THEY WERE MORE SUCCESSFUL COUNTING CALORIES ON LOW FAT THAN NOT COUNTING ON LOW CARB.”  The spontaneous reduction in appetite obviously didn’t cut it.  Do not be in denial of these cases.

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