Tag Archives: ketogenic

Cyclical ketogenic diet and carb refeeds

Potential conclusion (pending full texts): “if you’re gonna keto, no need to carb”

I think these three abstracts are all referring to the same studies.  I haven’t seen the full texts.  My takes are in italics, after each abstract.

Exhibit A. The Effects of an Eight Week Ketogenic Diet vs. a Cyclical Ketogenic Diet on Performance and Testosterone in a Resistance Training Program (Lane, Lowery, Volek, D’Agostino, Wilson, et al., 2015)

Introduction: Our lab recently examined the effects of the ketogenic diet (KD) compared to a western diet regarding strength related performance; additionally, free and total testosterone was evaluated. Individuals on the KD saw similar adaptations in strength and similar changes testosterone. Comparisons of the KD against a cyclic (CKD) in strength, endurance, and testosterone have not been previously demonstrated in literature.

Purpose: Therefore the purpose of this study was to investigate the effects of the KD versus a CKD on performance and testosterone in resistance-trained males.

Methods: Sixteen resistance trained males participated in the study (age: 23.5 ± 3.3; weight: 187.6 ± 32.6). Participants on the KD consumed 5% carbohydrate, 25% protein, and 70% fat for 8 weeks. The CKD group applied the same macronutrient ratio to their diet Monday through Friday, while altering the ratio on weekends (50% carbohydrate, 25% protein, 25% fat). A periodized resistance training program was strictly followed 3 days per week throughout the duration of the study with high intensity interval training implemented on intermittent days 2 times per week by all participants. Participants were placed on a 500 kcal deficit derived from basal metabolic rate determined by the Mifflin St. Jeor equation. One repetition maximum (1RM) strength was assessed on deadlift, bench press, and leg press at baseline with a repeat assessment performed Week 8. Strength endurance was assessed on the leg press at baseline and re-assessed at Week 8. Free and total testosterone was evaluated at baseline and at Week 8. An ANOVA with repeated-measures was used to scrutinize the effects of KD and CKD on dependent variables assuming group (KD and CKD) and time (pre and post) as fixed factors. The significance level was set at p ? 0.05.

Results: There were no differences between groups in the performance tests or testosterone levels detected at baseline (p > 0.05). A time effect was observed for bench press and deadlift 1RM (p < 0.01). There was a trend towards a group by time interaction (p = 0.07) which favored an increase in the leg press 1RM in the KD group. There were no significant differences for leg press strength endurance in both groups. For free testosterone, there were no group or group × time interactions (p > 0.05). For total testosterone, there was a group × time interaction following the diet treatment (p < 0.02). The pairwise comparisons revealed that only the cyclic group decreased in total testosterone (10.3%, p < 0.02).

Conclusions: In regards to performance, a strict KD seems to augment positive strength related adaptations when compared to a CKD. These responses may be explained by sustained total testosterone levels seen in the KD group compared to reductions in total testosterone as a result of the fluctuations in macronutrient intake.

Practical Applications: Individuals attempting to optimize adaptations in strength performance while maintaining testosterone levels should perform a KD compared to a CKD.

My take: no difference between KD & CKD, despite testosterone declining in CKD.  This isn’t surprising because small fluctuations within the physiological range are not expected to affect these outcomes.

When protein and calories are controlled, and the #context is a 500 kcal deficit, not really sure what they were expecting.  Because of the constant deficit, insulin will be low even on the carb-up days, and those carbs are more likely to be burned off than replenish glycogen.

 

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What or When to Eat

Artificial light at night, crappy sleep, and skipping breakfast are major contributors to poor circadian rhythms.  Some bro’s insist WHAT you eat is infinitely more important than WHEN you eat.  I beg to differ, at least in part – nix the refined & processed foods and it doesn’t really matter if you prefer low fat or low carb (P<0.05).  Evidence: Hunger-free diet(s).

 

Exhibit A.  On the other hand, feed two people identical diets but induce circadian disruption in one and whammo – big difference in outcome.

 

 

Significantly less fat loss and more muscle loss in the circadian disrupted group.

Interindividual variability? Yes.  Statistical significance? YES.

 

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Eating in the absence of hunger

Good idea? Bad idea? … a bit of a rant

Some gurus swear by the “only eat when hungry” mantra.  I’m neutral on the issue.  In my opinion, it can work for people who are good planners because if you wait until you’re hungry and haven’t planned or prepared a meal yet, then it might be a while until you finally get to eat.  Maybe you’re an hour from home: unlucky => by the time you start cooking, you’re famished and end up overeating.  So you try to repent by skipping breakfast the following morning but fall into the same trap.  Of course, however, it’s not gonna be like this for everyone.

 

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A timeline of ketoadaptation

This is how ketoadaptation works (when it works), chronologically, on physical performance (I think):

 

 

Dark grey line: the gradual increase in performance for someone training on a regular diet.

Red line: performance declines on keto initially, but is back to baseline (light blue line) by week 3.

Light grey line: as long as ketoadaptation doesn’t impair performance, similar gradual increase in performance for someone training on a regular diet.  Parallel to the dark grey line.  May even catch up to the dark grey line.  I don’t know, but probably not as per FASTER – long-term LC athletes were not superior to their LF counterparts.

 

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Protein, ketosis, and lean mass

Most people make a big deal about protein.  I do, too.  Low carb diets aren’t muscle-sparing.  Again.

 

 

Comparison of a Low-Fat Diet to a Low-Carbohydrate Diet on Weight Loss, Body Composition, and Risk Factors for Diabetes and Cardiovascular Disease in Free-Living, Overweight Men and Women (Meckling et al., 2004)

Part 1.  Hunger Free Diet(s)

Focus on what they’re eliminating:

LC diet: “limit intake of breads, pastas, rice, and desserts, eliminating intake of deep-fried foods, dried fruit, candy, sweetened soft drinks, and sugar, and increased consumption of vegetables, lean meats, eggs, and nuts”

LF diet: “eliminate high-fat dairy products and substitute with no-fat or LF alternatives, to increase intake of fruits, vegetables, whole-grain breads, and pastas and to eliminate fried foods, cream sauces, and high-fat/sugar cakes, pastries, chocolate, and candy. They were also asked to reduce use of oil products in cooking. As with LC subjects, LF subjects were encouraged to consume lean meats as alternatives to high-fat meat products.”

 

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Ketones, NLRP3, and IL-1 beta

Interleukin-1 beta: produced by activated M1 macrophages, classical fever-inducing cytokine, mediates cellular inflammation, and induces COX-2 (target of NSAIDs).  Also involved in autoimmunity.  You don’t want none of it but you certainly don’t want a lot of it.

The ketone metabolite beta-hydroxybutyrate blocks NLRP3 inflammasone-mediated inflammatory disease (Youm et al., 2015)

This is a very specific effect: 1) many structurally similar compounds don’t block NLRP3; and 2) beta-hydroxybutyrate doesn’t block activation of other inflammasomes.

 




 

“In vivo, BHB or a ketogenic diet attenuates caspase-1 activation and IL-1b secretion in mouse models of NLRP3-mediated diseases such as Muckle-Wells syndrome, familial cold autoinflammatory syndrome and urate crystal-induced peritonitis. Our findings suggest that the anti-inflammatory effects of caloric restriction or ketogenic diets may be linked to BHB-mediated inhibition of the NLRP3 inflammasome.”

 

 

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LCHF negates performance benefit of training. O_o

It takes about 3 weeks to become fully ketoadapted and you don’t really get more ketoadapted thereafter, at least as per max fat oxidation rates (which seems a pretty good surrogate, imo).

Important point: “Athletes who drop carbs cold turkey suddenly suck.”  And performance usually recovers by around week 3.  This has been confirmed in nearly every proper study on the subject, in a variety of contexts.

 




 

Which brings me to the latest alleged slam on keto & physical performance:

Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit of intensified training in elite race walkers (Burke et al., 2016)

 

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Ketones inhibit lipolysis

Petro just posted a brief article about acipimox & the insulin hypothesis.  Similar to insulin’s forte, acipimox inhibits lipolysis.  This leads to expansion of adipose tissue, and eventually, weight gain.

Acipimox acts on the same receptor as niacin and ketones, GPR109a.  That is, all three of those agents inhibit lipolysis.  We’ve discussed some of the implications of this on fuel partitioning HERE.

 

ketone-supp-physiology

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VEG*N

I’m not vegan but the “Anti-Vegan Because B12” argument is lame.  B12 insufficiency is largely due to malabsorption, not steak deficiency.

Many people take supps, but somehow anti-vegans think B12 invalidates veganism.  It doesn’t.  Also, 1) tons of B12 in oysters; 2) nori B12 works in humans and rats; and 3) mushrooms still haven’t been ruled out as a legit source.  Whether you consider these foods vegan or not is a different story.  Many non-vegans are B12-deficient, too -> all the steak in the world won’t help if you can’t absorb it.

I’m not undermining the severity of B12 deficiency, just noting some basic facts.

My bias: things like T2DM, obesity, and even some cancers and mood disorders are due primarily to circadian arrhythmia, sleep, & LIGHT… and secondarily to diet.

When it comes to diet, mostly plants plus some animal is optimal for humans in our modern #context, regardless of which Ice-Age Paleo-Fairy Tale™ you subscribe to.  Things like sleep, LIGHT, and activity, among others, seem way more important than debating historical [theoretical] dietary minutiae.

Lastly, this particular debate isn’t “vegan vs. keto.”  THEY’RE NOT MUTUALLY EXCLUSIVE.  “Eco-Atkins” is a thing.  Animals provide a convenient source of LC protein, but it can be done without them.

 

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The Hunger-Free Diet(s)

It started out as “lose weight without hunger on LCHF” and went all the way to “effortless fasting on keto.”  Works for some and it might be true, but the same can be said for low fat diets!  The key, I think, in both contexts, is simple: fewer processed & refined foods… something the Paleo movement got right, imo (although I still think many low-calorie sweeteners are way less unhealthy than HFCS & sugar).

The logic:

1) add “good calories” like almonds to your diet and appetite spontaneously compensates by eating less other stuff: energy neutral

2) you don’t compensate for added “bad calories” like sugar-sweetened beverages: positive energy balance

3) remove bad calories from your diet and you don’t compensate by eating more other stuff: negative energy balance

 

Book: Good Calories, Bad Calories

 

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