Carbophobes are everywhere. They’re here to stay. They love to talk about glucose as if it were arsenic, and fructose as if it were nerve gas. I should know. I’m one of them, or at least, I was. Every time you eat a banana, God kills a kitten. You can fuel the earth with ketones alone! Reactive oxygen species get released every time you eat sugar, and destroy every cellular structural element in sight. Every carb you eat gets turned into palmitic acid by the liver! You know what that is? A FAT! And not the good kind! The kind that gets plastered onto the rapidly-growing atherosclerotic plaques in your heart. And did I mention insulin? Good Lord, insulin! Who needs it? Nobody! Ketones ketones ketones! Rabble rabble rabble!
I’m looking for a bit of peace and serenity. To that end, I consulted the Perfect Health Diet to guide my measured transition from full-on Paleo to a sustainable, healthy, low-allergen plan that will keep me strong and lean, asthma-free, and most-importantly, sane. Today’s post is about carbohydrates, and what I learned about carb physiology from reading the PHD and some other sources.
Lesson I. Your Body Uses Carbohydrates.
Two major lines of cells in the body, neurons (brain cells) and neutrophils (the immune system’s anti-bacterial killers) preferentially run on glucose. Can they run on ketones, the fat-breakdown products that come with either fasting or a very-low-carb diet? Sure. Ketogenic diets are prescribed (rather successfully) to some patients with chronic medical conditions, especially severe epilepsy. It’s hard to say with the long-term effects of such a strict diet are, but kidney stones are definitely one of them, from what I’ve seen. And it’s hard to evaluate the effect on cognition in a kid whose seizures are so severe (usually from a brain injury) that his IQ is untestable to begin with. But the average adult body runs through 100-200g of glucose per day just to maintain neuronal energy and healthy immune function, including building-up of mucous membranes in the nose, lungs, intestines and everywhere – a snotty protective barrier against bacteria, built out of sugars.
So can you survive on fat and protein alone? If you were a lion with a giant liver, sure. If you don’t ingest enough glucose, your body turns protein into glucose. Sadly, not all of that steak is going to replenish your muscles. Not even a small percentage of it. Humans, apparently, don’t have as efficient a system for turning protein into glucose, and eating too much may strain the liver over time, and lead to chronic build-up of free ammonia (the by-product of amino acid metabolism). The PHD recommends 150g/day of protein as a maximum, and that’s only for people who are looking to maintain a lot of muscle mass.
Lesson II. Low-Carb Doesn’t Have To Be No-Carb.
So what are the thresholds of carbohydrate intake? Recent wisdom (from places like Mark’s Daily Apple) says to keep it under 50g a day to burn fat rapidly, 50-100g to burn fat slowly, and 100-150g to maintain a healthy weight. The Perfect Health Diet shoots for 15-20% of your total caloric intake, and at 2500 calories/day, that’s 100-125g. And these are actual carbs, as in glucose. Not 125g of carbs from collard greens or cauliflower. Glucose yes, fructose no. Fructose gums up many healthy metabolic pathways and leads to fat retention and insulin overload. And regular sugar is 50% fructose. Starches are your answer.
Sweet potatoes and root veggies > potatoes > white rice > other gluten-free grains.
Aside from rice, it’s surprisingly tough to eat 100g of these carbs. You know how many carb grams are in a large serving (a *large* serving) of McDonald’s fries? 63. You could eat 2 of these. Don’t, but I mean, you could. What about the insulin surge that comes from 120g of carbs a day? You slow it down by eating your carbs with a big dose of healthy saturated fat, like grass-fed butter or coconut oil. And besides, 100g a day of slow-digesting sugar is not the same as 400g a day of high-fructose corn syrup and refined flour.
It’s the big loads of fructose and sugar, combined with a relatively-insulin resistant state (that is, not after a workout or as the first meal of the day), that overload the system and cause conversion of glucose into palmitic acid and pack on the body fat.
Lesson III. Vegetables Don’t Count.
Yes, kale has 9 grams of ‘carbs’ per serving. Yes, a bag of frozen broccoli has 25 grams. As humans, our intestines have an unusual digestion plan for leafy green veggies (and other plant sources of dietary fiber). Your body actually has bacteria that take this vegetable fiber and turn it into short-chain fats for immediate energy sources. They don’t affect insulin levels much at all. The extreme case of this is in animals like cows and gorillas, who eat pounds and pounds of grass all day and don’t get fat. See that belly? It’s all intestine, full of bacteria, primed to turn grass into short-chain fatty acids (soon-to-be ketones) as an energy source.
So what did I learn, and how is this going to change what I do? I still plan to keep the potatoes and rice to a minimum and treat it like chocolate and fruits, in that I’m not going to freak out over munching on a few home fries or some rice in my soup. Potatoes get added into the diet regimen next week, followed by some white rice. I *do* love my sweet potatoes, though, and they’re going to be the post-workout food of choice. Again, no freak-outs about eating them at other times of the day.
I definitely don’t eat enough ‘carbs that count’, and in fact, the sweet potatoes may be the *only* non-veggie carbs I eat, meaning 50-60 grams, 3 days a week. So… not enough. It’s time to get over my fear, one potato at a time.