I have no problem with the Paleo diet

Many email exchanges between myself and friends on the topic of diet, activity, and health do not get recorded as entries in my little health blog, that I feel should. So, correcting the most recent example of that is the topic of this particular blog post, my response to a recommended blog. I am basically quoting directly from my email to my friend below:

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Taking some Q time this Sunday to look at John's blog, I like him, his blog is helpful and good. Bouncing around a bit I stopped on his weight loss plan

http://lifespa.com/dr-johns-weight-loss-plan/

I have no problem with the Paleo diet, because of enculturation and bias it is probably the most accessible solution for many with diet related health problems. That makes it "best" from a practical perspective, perhaps. But from an absolute standpoint I feel a correct reading of the evidence, anecdotal and scientific, points clearly to the high-carb low-fat approach as the cause (with other factors of course) of the highest levels of health possible. But I also recognize that a diet that cannot be done, for whatever reason, is no help at all, and so back to "what works", a variable depending on who and where we are right now.

But I am still interested in helping others see the memes of "carbs make you fat", and "fruit is bad for you, too much sugar", are simply wrong, on an absolute basis. How does this meme survive when it is abundantly clear the leanest (and arguably healthiest) folks on the planet, now and historically, are high-carb and low-fat cultures?  Answer: we have been confused by marketing, misunderstanding, and pre-existing biases.

Getting to specifics:

In the first paragraph I agree completely with the first sentence, but the remainder of the paragraph he presents several ideas that are very debatable.

First, while fat is the longest lasting fuel (is that what he means by efficient?), it is not the most efficient conversion of food to usable fuel by far. As you probably know, except for brain cells which need glucose to function, all cells burn a combination of fat and glucose, with oxygen, for fuel, when glycogen is available. The ratio varies depending on what's happening, but it averages about 50% fat vs sugar. Fat can be converted to glucose http://www.livestrong.com/article/440138-can-fats-be-turned-into-glycogen-for-muscle/

and ketones (the other sugar like fuel cells can use), but it is considerably less efficient than the conversion of carbs to glucose, in particular fructose and other simple sugars.

You probably know for example that an endurance athlete running out of glycogen cannot restore reserves by consuming fats, the conversion is too slow. He/she must consume carbs to restore glycogen reserves (in midst of ongoing activity). Fruits and sugar water are both efficient, and most modern endurance athletes use some form of sugar water, but are increasingly turning to fruit, and finding they perform better (who woulda thunk it:)

You probably also know that individuals in full blown ketosis cannot perform at their normal levels either physically or mentally.

Kevin (link below) is a good example of what happens to folks who do the raw-vegan low-fat lifestyle consistently and correctly (and as Kevin points out, the "cooked" version of low fat vegan works nearly as well). objective medical measures, and across the board performance levels go well thru previous ceilings. Why is that? it's pretty simple actually, and it has to do with conversion efficiency combined with nutrient density.... conversion efficiency depends not only on how much work the body must do to get fuel to the cells from any given food source, but also how much energy is spent on digestion vs fuel and nutrition resulting.

BTW there is no such thing as a low-fat diet that includes animal products for the simple reason animal products are typically very high in fat, for example, in eggs, a commonly cited "high protein" food, the actual calorie breakdown (available energy in the egg) is 61.9% fat, 35.5% protein, and 2.6% carbs, almost twice as much fat as protein.

Short vid with Kevin showing "a day in the life"

https://www.youtube.com/watch?v=sM3slLVmhp8