I am devoting this week of posts to an important topic that I talked about with Jimmy Moore on his Livin’ La Vida Low Carb Showpodcast, specifically the very individual nature of carbohydrate requirements. I want to use the written medium of my blog posts as an opportunity to expand on this topic in a more succinct fashion, and to open a discussion with you should you have any questions. When Jimmy asked me what I thought about safe starches and ketogenic diets (two extremes of paleo diet carbohydrate consumption), I answered that I believe there is a fairly large variability from person to person on how many carbohydrates (and what types) each person needs for optimal health. I encourage self-experimentation to determine what carbohydrate range is optimal for each individual.
Carbohydrate consumption recommendations vary from eating as much non-starchy vegetables and fruit as you want (The Paleo Answer) to eating almost no fruit but consuming lots of “safe starches” (Perfect Health Diet, Mat Lalonde, Chris Kresser) to limiting both fruit and starchy vegetables and sticking fairly low-carbohydrate (The Paleo Solution, It Starts With Food). One of the reasons why people come to such different conclusions as to how many carbohydrates should be included in our diet is because historically studied hunter-gatherer populations consumed dramatically variable macronutrient ratios from the Eskimos, whose diet consisted of approximately 90% animal protein and fat and only 10% carbohydrates, to the other extreme of the Kitavans, whose diet contained only about 10% protein but 70% carbohydrates, mainly from starchy tubers. Just about everything in between exists, although 10-30% of calories from carbohydrates seems like a fairly common occurrence in hunter-gatherer populations (see analysis in Perfect Health Diet, this post by Drs. Jaminet and the referenced paper 1). Okinawans, who are currently the longest-lived humans, consume about 50% of their diet as carbohydrates, typically from starchy tubers (and eat lots of fish and pastured pork) 2. The takeaway message here is that humans can adapt to a wide range of carbohydrate intake if they are avoiding foods that cause inflammation and irritate the gut and if they are eating a balanced omega-3 to omega-6 fatty acid ratio.
I love low-carb diets for weight loss (it’s been absolutely essential for my own weight loss). I lost most of my weight while consuming between 30g and 50g of carbohydrates per day. However, I find that I need more carbohydrates these days (somewhere between 75g and 100g per day works well for me). If my carbohydrates dip too low, my cortisol increases too high and I start to gain weight and have trouble sleeping. Chris Kresser reports (here) that some of his patients who have come to him on low or zero carbohydrate diets experience increased weight loss when they increase their carbohydrates a little. This seems to have been true for me, although 100g of carbohydrates per day is still quite low, especially compared to the typical carbohydrate consumption of the Standard American Diet which is in excess of 300g per day. Many people thrive on low to moderate carbohydrate diets as a maintenance diet (anywhere from 50g per day to 150g per day). On the other end of the spectrum, some other people thrive on ketogenic diets (very low carbohydrate and moderate protein) and these diets can be extremely powerful in addressing some specific health conditions (more on this in a future post) and for propelling weight loss. You’ve probably noticed a contradiction here already. Some people find ketogenic diets propel their weight loss while others find that ketogenic diets stall their weight loss. The difference is likely due to regulation of a variety of hormones, but probably most importantly, cortisol management. Ketogenic and very low carbohydrate diets necessarily increase cortisol expression in order to create glucose for the few cells in the body that cannot run on ketone bodies. In the absence of adequate sleep, adequate stress management, adequate sun exposure, and any other factors that may affect cortisol management, ketosis can lead to complete derailment of cortisol expression. I believe that cortisol management (because my kids still get me up several times per night most nights) is why my body is doing better on more carbohydrates these days (I also think it’s why my body refuses to lose the last 10 pounds that I want to lose). Independent of cortisol issues, there are also other people who simply need more carbohydrates (kids, endurance sport enthusiasts, athletes, older people). What type of carbohydrates you consume is fairly individual as well (if you have SIBO, you’ll want to avoid starchy veggies; if you have a history of metabolic derangement, you’ll want to be mindful of your fructose intake; if you’re an athlete you’ll want to consume more starchy vegetables).
So, how exactly do you figure out what is the best carbohydrate intake for your body? The easiest way is to try a few different levels of carbohydrate consumption as well as types of carbohydrate (non-starchy vegetables versus starchy vegetables versus fruit) and time of day of carbohydrate consumption. See how you feel. Change and see if you feel better or worse. Change again and see how you feel. Go back to the first carbohydrate level and see if it’s how you remembered it. (I am assuming here that you are relatively healthy. If you are dealing with disease, then I think figuring out what foods you need to eat to heal is more important than figuring out your optimal level of carbohydrates.) It may take several months to narrow in on your perfect carbohydrate intake range. And if you are challenged with certain health issues or are actively losing weight, it might be a moving target. I suggest keeping written records of what you are trying, how you feel, and anything else you might think is relevant. In my next two posts I will provide details to guide you through this self-experimentation strategy for determining your optimal carbohydrate intake. There are two questions to be answered here. What level of carbohydrates does your body need to run optimally? This might include anything from performance at the gym, sleeping well, losing weight efficiently, managing stress easily, having energy and feeling happy. Then there’s the level of carbohydrates that your body tolerates. How low can you go before you start to see adverse effects? How high can you go before you start to see adverse effect?
Note that I only suggest that you embark on this process of self-experimentation if you are fairly healthy (it’s okay if you have weight to lose), if you are not consuming gallons of coffee to get through your day, if you are sleeping at least fairly well, and if you can keep your food intake relatively consistent from day to day. The goal is to figure out the range of carbohydrates that you can consume and be healthy. Then as you practice eating your optimal level of carbohydrates, you can learn how to shape your meals so that you don’t have to count carbohydrates or really think about it anymore. By the end of this process of self-experimentation, you should be able to intuitively eat the right number of carbohydrates for you!
1 Kaplan HS, Hill KR, Lancaster JB, Hurtado AM. A Theory of Human Life History Evolution: Diet, Intelligence, and Longevity. Evolutionary Anthropology 9:156-185, 2000.
2 Sho H. History and characteristics of Okinawan longevity food. Asia Pac J Clin Nutr. 2001;10(2):159-64.