Carbs, Carbs, the evil carbs…
September 13, 2010 16 Comments
Go for it!
A while ago, I wrote a blog post about the role of carbohydrates in the paleolithic diet [link here]. The take home point was that the amount of carbohydrates you should eat depends on who you are. Since then, I have been asked about my opinion on carbs. In today’s post, I will address my reader’s question in details. [As a side note, if you have any questions, feel free to contact me by using the contact button at the top right of the website]. Until now, I haven’t really taken a stance on the subject. This is due to the fact that I think that personalization of the diet is what matters. Obviously, people read blogs to know the opinion of the author, so here is mine.
Carbs and me : my unbiased opinion of carbs
A lot of – what I would call – naive judgment of carbs is being done all over the Internet (not just in the paleosphere). Nowadays, fat is less and less evil while carbs are getting a bad reputation. That’s the marvel of the human mind : we all have beliefs and we all create our own imaginary battles. Sometimes, it helps to make the debate progress. Other times, it just stops progress. That’s how it is and we can’t do anything about it.
Still, when we believe in something so much that we start to believe that it is the universal truth, we lose contact with the goal of our methodology - which is to find the truth. Selling ideas or things is completely different than finding what is right or true. Concretely, in science, the goal is to prove that our hypothesis is wrong. If it’s not wrong, then there might be a link. If it is wrong, then there might not be a link. Pretty simple, right?
Yet, when you look at how things are done on the Internet (and sometimes in books), you can see this methodology is not always applied. Scientific integrity and the avoidance of bias are the most important factors of this methodology. Anyhow, instead of proving their hypothesis wrong, bloggers, science amateurs, diet gurus and sometimes real scientists try to prove their opinion right. This makes up for a very biased read and it may actually send out the wrong message. This is important to keep in mind when it comes to understanding the carbohydrate debate.
Let’s get to the point here: this type of bad methodology created a lot of misconceptions around carbohydrates, so allow me to debunk some of them.
Don't go for it!
In the case of fruits and vegetables, they bring a lot more to the table than carbs. They bring nutrients, anti-oxidants and they have a base effect in your body. No one is going to say that nutrients and anti-oxidants aren’t essential. A base effect from foods is probably essential, since protein foods (read : no or low carbs foods) are acidic. We need more research in this domain at the moment, but a point can still be made : natural carbs are not essential, but they still bring essential nutrients.
Considering that vegetables and fruits have little impact on the level of insulin of an healthy person, and the amount of healthy compounds it brings, it makes no sense to limit the amount we eat (we still should make meat the focus of our diet, though). I guess we could say that they are not essential to humans to survive, but they are highly recommended for optimal health, which brings me to my next point.
Ketosis is often pointed out as the solution to our health problems. Science shows that it can be very helpful with certain conditions such as epilepsy. Ketosis is basically our biologic ”back up software”. When you run out of glycogen for a certain period of time, your body starts to produce ketones (via ketogenesis) and uses that as energy instead. This is a marvel of human physiology. It ensures that we survive in times where food is rare and where glucose is rare. But is it optimal to run on ketones alone ?
We don’t know for sure. Clinical data show that people can improve their condition in some cases, while in other cases it’s not that good. However, I believe that ketosis is a back up system and it should be used the way it was designed. To me, there is no real reason to not eat any fruits and vegetables (and, as we have previously seen, their anti-oxidants and nutrients). Plus, it’s actually counter-intuitive to avoid fruits and vegetables considering that they have been part of our diet for more than 6 millions years (from small to large quantities, that is)!
Did you really think that these guys simply said no to plant foods?
Another point we need to address is that there are no real data proving that our ancestors had a very low carbs diet (unless there were situational restrictions). Studies of modern hunter gatherers show that most of them enjoy a moderate amount of carbohydrates [link to Matt Metzgar's post on this subject here]. It’s important to understand that humans can survive on about any diet (hey, we do survive on processed foods right now, right?). But, the optimal choice is a balanced diet based on real foods. I have yet to find a real whole food that is not worth eating.
The bottom line is this : carbohydrates in large quantities and from bad sources are to be avoided. Moderate amounts of vegetables, fruits and arguably tubers, are probably fine as long as you don’t have any health conditions that require you take precautions. Also, very low carbohydrates intake could be potentially dangerous if it’s done in a sloppy way. Finally, generalization is to be avoided when it comes to carbohydrates (more on that tomorrow). I really hope people can realize that evolutionary eating is not about hating any nutrients. It’s about eating the best foods available and avoiding those that are problematic. Fruits, vegetables and arguably tubers, are not problematic for a large percentage of people, so they should not be avoided.
As a side note, to clear up the potential confusion, it might be worth noting that in no way I would recommend eating large amount of carbohydrates - unless you are an endurance athlete (again, more on that tomorrow). Understand that what I am trying to say here is that carbohydrates are not evil if they come from natural sources (plant foods) and if they are eaten in moderate amounts.
Nicely written. I have a hard time convincing people that their “whole grain” wheat bread, cereals and pasta are nutritionally poor, crap food. It’s all about nutrient dense food and the ability to get more nutrients out of a smaller amount of real food.
Thanks for sharing, looking forward to tomorrows too
) Since Jan I’ve been under 100 close to 30 to 40 carbs a day an I feel pretty good 
)
So what are your views on fructose if we don’t limit fruits?
hi Rip,
I feel that processed fructose (high fructose corn syrup) is to be avoided. In the case on fruits, fructose is not a bad thing in my opinion. First, carbs from fruits are not just fructose. Two, scientific data is very bogus and I would much prefer to rely on evolutionary thinking at the moment (our ancestors enjoyed it and we probably should too (unless we have a condition)).
I go back and forth in regards to fruit almost daily. I read often online that our ancestors did not have access to much fruit. And when we did it was mostly berries. Also, fruit in todays world is a lot sweeter than what it was before agriculture – much sweeter.
So I guess this is why so many say to limit fruit to berries. I love fruit but eating too much does lead to a lot of carbs.
Much sweeter is not the way to put it. Our fruits are bigger because of the breeding (you pick the bigger fruits when you want to grow some). It does not necessarily means that you should not eat fruits. Our ancestors probably ate more than a single fruit (need more to have the same energy as a modern fruit) whereas we eat only one. This is just my hypothesis.
Excellent points here. I know I became a bit overzealous once I saw the mainstream “calories / fat / sat fat / cholesterol are all evil” paradigm dismantled (thank you GCBC). I wound up on the opposite side of the spectrum, believing carbohydrate to be inherently unhealthy (again, thank you GCBC). As you noted, vegetables and fruits such as tubers and berries would have played a part in our evolutionary diet. I think this is just another nail in the coffin of nutritionism – making decisions on what food to eat based on the nutrients they contain rather than vice versa.
Hi Darrin, thanks for your comment.
I agree with you a 100%. Just because some nutrients are bad in large amount (carbs) does not mean they are not bad in moderate amount. And, then you really have to take into account the type of carbohydrates you eat (grains vs vegetables). You are spot on!
Wow, what a great post. I totally agree with your view on the subject. That is exactly the point. I guess that how many carbs depends heavily on each subject. Some people is very sensitive to carbs, while other tolerate higher amounts.
One question to be considered though is that almost all moderns fruits has been artificially selected by agriculture to taste much more more sweeter than their natural counterparts. What do you think about that?
Aitor,
As long as you keep it moderate (don’t base your whole diet on fruits), there are no problems in my opinion. Dr. Cordain demonstrated that watermelon (the fruit that is probably the highest in sugar, especially fructose) has little impact on insulin levels (glycemic load around 3.5, if i remember correctly). This does not mean we should eat all we want but I see no problem in enjoying a piece when it’s in season.
It really is a matter of context and seeing the whole picture. For isntance, some paleos drink beer. Alcohol is not something we are able to digest. It also have gluten. It could also have estrogenic effects on us. And, yet, they are not really willing to give it up (good refreshing drink, taste good, makes us relax, etc.). In this perspective, a beer is probably more harmful than a piece of fruit is. It does not legitimize the choice to eat fruits but it does show that it’s a matter of context (goals, health conditions, etc.).
The moment you are able to make your diet flexible by enjoying a great variety of foods, you break free of diet rules. Concretely, our ancestors did enjoy sweeter foods once in a while (such as when they found honey). It does not mean their diet was based on these foods, it just means that sometimes they ate foods with more sugar in it.
Thank you. Regarding beer do you have more information about it. I’ve been unable to find a good study including components, types of beers, GI, etc…
My stance was based on what I know of alcohol metabolism and what I know of gluten. I don’t think I have seen a study about different types of beers but it would be nice to read it (if it’s available).
JP, I really like your approach towards nutrition. Of everything I read on the internet that makes me confused, I come back here and it always makes sense. I don’t avoid carbs for carbs sake, but I try to avoid empty carbs like you said, and get the most nutrients. I was watching a show about some hunter gatherer tribes that are still around today, and it showed them catching an animal, cooking it and eating it, and then they found some tubers and ate those too. They were all very lean and fit!
Carla, good point!
tubers are very, very paleo (strong evidence of consumption). More than some experts would care to admit it.
Another awesome post JP.
I was thinking along the same lines last night and then voila! I followed a link to this post. Nice bit of coincidence.
(I wrote a post about it this morning.)
Thanks a lot Kay.
I will check out your post right away!