Information on fat adaptation

[Ivan Pellejero]

I'm a nutrition student and today I talked to my biochem teachers about the fat adaptation process exposed in the metabolic diet book, well, they where interested but mostly they where quite full of doubts about it, doubts I saddly couldn't erase. They wanted to know how the body did the change in the metabolic pathways, what happens in the cells. I need studies if available, or at least theories regarding the metabolic changes and adaptations. For the sake of my credibility haha, they may see me as a credulous person from now on, I dont really care because there is ample experience showing it works, but it would be great to have some backup.

[Larry Roseman]

Did you explain it in terms of ketosis and ketogenic diets? They should understand those....

But in any event unless you have a condition that requires you to eat that way, it's probably better

not to. It's a survival mechanism to minimize muscle loss during starvation, not meant to improve

outcomes of strenuous activity. If you do lose fat mass specifically, by whatever means,

when you resume eating normally, eventually you should be able to perform better at a higher strength to weight ratio.

[Joshua Naterman]

Did you explain it in terms of ketosis and ketogenic diets? They should understand those....

But in any event unless you have a condition that requires you to eat that way, it's probably better

not to. It's a survival mechanism to minimize muscle loss during starvation, not meant to improve

outcomes of strenuous activity. If you do lose fat mass specifically, by whatever means,

when you resume eating normally, eventually you should be able to perform better at a higher strength to weight ratio.

There are a number of issues with relying on fat for fuel, but there's a great study from 1983 that you will probably misinterpret. The keys are what is glossed over.

Short version: Experienced endurance cyclists were switched from their normal diets to a diet of 85% fat and 15% protein for 4 weeks. RER dropped by quite a bit during exercise from pre-week 1 to week 4 final workout.

T3 levels dropped. This is very, very easy to miss as it is not on the chart and is mentioned in 1 sentence halfway through the discussion. The excuse given is that it is instrumental in the muscles using glucose and thus may be perceived as a positive adaptation. That is NOT a positive adaptation, it is a glucose-sparing adaptation at best and that is not synonymous with either good OR bad. What IS bad is that T3 is something of a master hormone. You will have to read more on T3 to learn what that means.

The amount of glucose used during exercise dropped approximately 75%, and the same intensity was maintained.

KEY POINT: The intensity was 62-64% of VO2Max. That's frikkin' not high intensity, and not even close to a well-trained athlete's lactate threshold. In short, this diet was used with fairly moderate intensity training that did not even begin to approach the intensity where your body relies exclusively on carbs to sustain the energy output.

High intensity endurance activities can't be sustained at maximum output with this kind of diet, and neither can high intensity anaerobic endurance exercise.

Final point I will make about this study:

It was observed that by the end of the study insulin concentration in the blood rose dramatically during and after exercise, yet blood sugar remained unchanged.

Translation: THEIR BODIES COULD NOT RESPOND PROPERLY TO INSULIN. Holy crap! I just don't know what else to say. It is unbelievable that people have tried to use this to say that Paleo is "The Way." This is, in fact, one of the main studies that was used to promote the Paleo lifestyle.

Which, by the way, is being revised because they are realizing that they suck at high intensity endurance and anaerobic endurance due to insufficient carb intake.

I might be able to get a reference for you in the next month or so but you should probably look up "1983 ketogenic" on pubmed and see what comes up.

http://www.ncbi.nlm.nih.gov/pubmed/6865776

http://www.ncbi.nlm.nih.gov/pubmed/6865775

Now, that second one is even more awesome. Blood glucose levels are ~10% lower and total cholesterol... wait for it... goes up 33%. From 159 to 208. Begakin! And they have the nerve to say that serum lipids were not "pathologically elevated."

[Ivan Pellejero]

I actually waited for it...Many thanks for the info, as for now and probably ever, no metabolic diet nor long periods without carbs diets, just plain good ol' carbs at the right time, plenty of good fats and protein. This saturday was the first carb refill of the metabolic diet, I might be close or even slightly fat adapted by now :|, I call this a cheat meal night.

And why are the studies always about cyclists? Are there none about power or strenght activities? But from what I saw this kind of diet kills your strenght. Then why Di Pasquale claims that it will improve one's performance in sports such as powerlifting? :shock:

[Larry Roseman]

I don't think anything Josh said was addressed to me, and was just adding *a lot* to my comment. Yes?

One way low-carb eaters do survive more intensity or duration is to eat carbs around the workout only, so they

"kinda don't count". I believe this is the "paleo for athletes" approach involving "clean carbs". Paleo shouldn't be so low carb as to lead to ketosis though and shouldn't be as bad for performance as true low-carb. I mean you do have a lot of crossfitters eating that way and many of them are in great shape. Though, I gotta agree that they will hit a point eventually where it strangles them.

[Joshua Naterman]

I actually waited for it...Many thanks for the info, as for now and probably ever, no metabolic diet nor long periods without carbs diets, just plain good ol' carbs at the right time, plenty of good fats and protein. This saturday was the first carb refill of the metabolic diet, I might be close or even slightly fat adapted by now :|, I call this a cheat meal night.

And why are the studies always about cyclists? Are there none about power or strenght activities? But from what I saw this kind of diet kills your strenght. Then why Di Pasquale claims that it will improve one's performance in sports such as powerlifting? :shock:

Short-duration strength athletes like sprinters, gymnasts, powerlifters, etc don't need full glycogen stores. Endurance athletes do, for top performance at high intensity. I don't think you will ever see a 60 second Wingate test comparing low carb with high carb, because that will let the cat out of the bag and none of the people whose income relies on people buying into a low-carb approach will sponsor research that leads to poor results for them.

You can't be super low carb as a powerlifter, but with carbs being concentrated a bit more around the workout they can probably stay leaner and this leads to a better relative strength. Not going into too much detail on this point. Sorry.