Thursday, April 4, 2013

Logical Fallacies and more thoughts on paleo

Consistency and habit

I am sorry that this blog has been quiet recently, but I've just not been finding things to post: either items that I wanted to highlight here or things that I wanted to write.  I've been distracted by other things - like climbing hills in the sunshine and snow - but also I have been aware of the fact that sometimes there is not really much to say.  In recent posts I've pointed to the idea that consistency and habit, patience and persistence trump most things when it comes to fitness and health.  There is only so many times that you can say this before it gets boring.

Logical Fallacies

When I have been thinking about "fitness" issues I've actually been reflecting a lot on how limited my outlook has been for so long and how this might have been affecting my results.  A lifetime ago - or so it seems - I did a degree in Philosophy.  I did three years worth of formal logic, which was one of the parts of the course that I really enjoyed - the analysis, the equations into which arguments were broken down and expressed.

Recently I've been thinking about logical fallacies - errors in reasoning, arguments that might look valid at first but which on deeper consideration are actually invalid:  the conclusion does not flow from the premises.  There are lots of lists of such fallacies but Your Logical Fallacy Is...  sets out a good few.

For example:

personal incredulity

Because you found something difficult to understand, or are unaware of how it works, you made out like it's probably not true.


the idea of an argument from silence:  the absence of evidence is not the evidence or absence.....

Your exercise routine / diet is based on an invalid argument

Anyway, I suppose this gets me to some more thoughts on Paleo.  The Paleo backlash is now underway with videos like this:

or Marlene Zuk's Paleofantasy (interviewed here)

I actually think the best analysis was done - with a good sense of humour - by Matt Stone in

12 Paleo Myths: Eat Better Than A Caveman 

Reading that and thinking through the arguments a lot I came to realise that a lot of the dogma was just wrong.  In terms of the logical fallacies we were so often at:

appeal to nature

You argued that because something is 'natural' it is therefore valid, justified, inevitable, good or ideal.

The whole grok thing, spinning an ideal of how we were intended to sounds good, it sounds romantic but either there is nothing to it or else it is just banal obvious statements.

Common Sense

I was trapped in a paradigm for a while there, seeing everything through the "primal" lens.  Now I am realising that I was being stupid to be so limited in outlook.


Unknown said...

I never bought into the grok stuff as far as exercise goes. Running barefoot ... I have been running with running shoes since 1979 and never had an injury, so wtf is wrong is running shoes?

I've got a bunch of non-runners who weren't even BORN when I started running telling me I have to run barefoot because it is "natural."

That's all well and good but I've got over three decades of experience under my belt, how much do they have?

August said...

It feels a lot more like she's knocking down a bunch of straw men to me. Most of the stuff she talks about can be found on various blogs- paleo blogs.
I also don't get the 'trapped in a paradigm' thing. Maybe that's because I came from Seth Roberts' world where the idea was self-experimentation and evolution helps me come up with hypotheses to test. A lot of the stuff worked. Some stuff, like the extremely low recommendations for sodium, didn't. They made an educated guess, but they were wrong- probably due in no small part to modern biases, but still it was a reasonable guess based on evolution and the available data. Zuk isn't bringing anything new to the debate, and I view her as little more than manipulative.

Anonymous said...

I think this is a good smack down of the "fad" paleo diet world but Christina Warinner winds up embracing some basic (real) paleo premises in the end:

Dietary diversity is the key, eat fresh food, eat whole foods.

She does go off into the weeds in places:

In critiquing paleo diet thinking by comparing humans to carnivores. No one in the paleo world is saying that we are carnivores. We are omnivores.

In accenting grains as an ancient food source. Gathering and grinding grains in any quantity would have been far too labor intensive to make it a significant food source. Discovering some grain sources in plaque does not refute this.

And lastly, the common error of thinking that lean muscle meat in wild animals translates into low animal fat consumption. Our ancestors ate the entire animal which contains a much higher fat content than in the muscles meat and prized that fat.

She IS embracing a "primal" lens (Chris) while doing a good job of modernizing it by bringing to light that in a modern world indigenous food sources are uncommon, won't feed the planet and have been supplanted by modern foods which are often nutritionally richer.

Unknown said...

Marlene Zuk didn't really offer valid counterarguments, or rather she fought a beast that wasn't even there in the first place, Matt Stone did much better job. After reading his book there is no way I would consider Paleo or another trendy diet. I am kind of ashamed I didn't recognize the flaws in this before, although the signals were strong. I even thought professors at medicine aren't really digging deep enough to discover these interesting evolutionary concepts. Lol:-)

Nate said...

Chris - I appreciate your whole recent "common sense" theme. However, I actually think its a little ironic in that I think the ones trying to debunk paleo tend to make matters slightly more complicated. If you boil paleo down to one sentence, its "Eat meat and plants". You can not get more simple than that. All the other stuff (what meat, what fruit, what excercises, grass fed, raw, etc.) are simply people experimenting, because people tend to be curious by nature.

"Common sense" to me says one would have a hard time going wrong eating mainly meat and plants. Those trying to justify grains, for example, are making matters a little more complicated.

I don't think any reasonable paleo person would argue against moderation or indulgences. But I will likely never be convinced a diet made up of a lot of grains is the way to go. Again, a pretty simple concept if you ask me.

Ferry said...

I can not find any new stuff in the talk.

Root ideas of Paleo movement can not be wrong as they are based on evolution. Paleo should not be restricted only to diet. The core of Paleo idea is, as far as I understand, to see how our ancestors have lived and what can we learn from their way of life. Genetics play a big role and can never be ignored in our observations.

Science still can not deliver proper answers to all modern issues and diseases. Evolutioary perception could be a way to find some reasonable ideas.


Anonymous said...

Really everyone that has argued against the paleo diet, including Matt Stone, has never had a valid argument. It's like trying to argue against strength/resistance training. Not a particular protocol, or particular equipment, or particular form, but strength/resistance training itself.

The paleo diet is a framework and is more about what foods to avoid, not what to eat, though that is important as well.

Bread should be avoided because it has harmful ingredients, and is devoid of nutrition.

Broccoli, as far as I'm aware, is nutrient dense and not toxic/harmful in proper amounts. So you can eat it. It doesn't matter if it's different then paleolithic broccoli. Coconut oil, butter, dark chocolate, and coffee didn't exist in paleolithic times. I don't see a reason to avoid them.

Even one of her initial arguments about humans having longer digestive tracts then carnivores so therefore we must eat more plants fails to compare humans to other primates. We have much smaller digestive tracts then other primates.

We eat more calorie and nutrient dense animals, and not very much vegetation and fiber, so we don't need a large digestive tract like a big bellied gorilla. Cooking also contributes to making digestion easier for us.

Less time and energy spent digesting, and a smaller digestive tract is one of the reasons we have a bigger brain then other primates.

Unknown said...

Paleo diet is a commercial diet of elimination. Before the ebook craze, it was hardly considered to be a foundation or a framework. My grandma would kick me in the balls if I refused bread, pasta or milk:-)

Anonymous said...

Well bread and pasta suck. Not just because of the bad stuff like gluten, but there's no real nutrition in it. I understand some people want to eat it for traditional reasons, but neither of my grandmothers are healthy, so I'll start my own tradition.

Milk can be good, if raw especially.

Paleo is supposed to be based on evolutionary biology, so it was always considered a general framework and would evolve so long as our understanding of evolutionary biology would. No one could really claim the diet as their own for that reason.