Kale vs Chocolate: Surprising Impact on Blood Sugar

Kale spikes my blood sugar more than chocolate. I know, it's insane, but it's true. And you know what's even crazier? It might be true for you as well. Now, this video isn't about just hating on kale, although there's going to be a little bit of that. It's about revealing how individualized our responses to food really are, and then empowering you to probe the secrets of your body for yourself. But first, let's quickly discuss the idea of a glycemic index and a glycemic load, so you know what these terms mean. These are measures of how much a food spikes blood sugar. A glycemic index is a number between 0 and about 100, with 0 suggesting a food doesn't spike blood sugar, like an egg, and 100 being equal to pure dextrose sugar. And glycemic index is based on a standard portion size, whereas glycemic load also considers the amount of the food actually eaten. So while a glycemic index of a banana is of around 50, the glycemic load of 2 bananas is twice that of 1 banana, even though the glycemic index stays the same. Hopefully that makes sense. But here is the rub. These aren't actually fixed values. For a person. They're numbers based on averages from groups of people. In reality, your blood sugar response to any given food is highly, highly individual. This was proven in a landmark study published in the journal Cell in 2015, which showed that people's glycemic responses to the same foods were so different that one person could spike from a cookie, but not a banana, and another person could spike from the banana but not the cookie. Same exact foods, but opposite reactions in different people. And this matters, because the more your blood sugar rises and falls, the more your hormones, in particular the hormone insulin, go on a rollercoaster. And they can drive hunger, even change how you burn energy and where you store calories.— as fat, as muscle, or burning it off. So yeah, this really matters. Now, from wearing a continuous glucose monitor myself, I've noticed over time that kale consistently spikes my blood sugar by about 30 mg/dL, despite having a low glycemic index of 15 at a general population level. So, I decided to have some fun and compare it to chocolate. To get robust results, for me personally, I tested kale and chocolate 3 times each on 6 different days. I used 2 different chocolates, a 95% dark chocolate, a stone-ground chocolate from the brand Teysa, which is my go-to, no affiliation, and a 73% dark chocolate. I did not try to carb match them. I actually ate the amounts a normal person might. So for kale, I cooked down about 4 cups of raw leaves, which amounts to about 8 grams of net carbs. Not much at all in terms of net carbs. And for the chocolate, I ate the bars because real people don't eat just one square. And if you do eat just one square, please feel your forehead for me. You might find there's a unicorn horn there. Anyway, the 95% bar was 2.5 ounces and the 73% bar was 2.1 ounces, with net carbs of 12 and 27 grams respectively. So if there was bias, and there was by design, it was in favor of chocolate spiking my blood sugar more, not kale, due to the higher carbs and the higher glycemic index of the chocolate. But that is not what happened. To the contrary, the kale reliably spiked my blood sugar, and the chocolate never spiked it more than 21. Isn't that interesting? So, why? Well, I don't have a perfect answer, but I can offer informed speculation. And I'll explain why that matters. But first, remember the Cell paper I mentioned earlier. Someone reacted to a cookie but not a banana, and someone else had the opposite effect. Individualized responses to food are not the exception. They're the norm. Really internalize that, because it's super important. But now, back to the kale. Some data suggests that fiber can be inflammatory in certain people. If you want more on fiber, see this video. I have a whole breakdown on fiber. So it's possible that particular fibers in kale caused an inflammatory, um, immune, a stress reaction in me that bumped my blood sugar as part of a systemic stress response. This makes sense to me because a spike of up to 36 mg/dL seems disproportionate for just 8 grams of net carbs. That said, if you're mathematically inclined, it's actually not impossible on basic math principles. So if I have 5 liters of blood, as a normal human, in my body, that's 50 deciliters, and 8 grams of carbs is 8,000 milligrams of carbs. Of sugar. So if you distribute 8,000 in 50 deciliters, then it's 8,000 milligrams over 50 deciliters, which is 160 milligrams per deciliter. So it's possible. And just for kicks, for more math, if you took the sugar from a 12-ounce soda, which is 39 grams of sugar, and dump that into the human bloodstream all at once— don't do that— but you'd get 39,000 milligrams over 50 deciliters,, which is a 780 mg/dL theoretic bump. Kind of wild, right? We don't actually have that much sugar in our blood. But back to kale. Even though 8 grams of carbs isn't much, you'd expect slower absorption and for the muscles and the liver to help clear some of that glucose. So a spike of up to 36 mg/dL for 8 grams of carbs is still pretty odd. One explanation, as I mentioned, is an inflammatory or immune response. To certain fibers in kale. That's possible. But kale also contains other compounds that can cause stress responses, like oxalates and phytates. I'm not even saying these are bad or trying to fearmonger about them. I'm just pointing out the central truth that people do have individual responses to different natural compounds in our foods. That's actually not an extreme statement if you think about it. Honestly, I think it really comes down to an idiosyncratic, a personal reaction. My body just doesn't vibe with kale. My body is just like, "No likey." Now, the astute observer might be yelling at the screen, "Nick, you dope! Chocolate also has fiber and oxalates. Your theory tastes as bad as raw—" Well, you get the joke. So thank you, astute observer. You're actually right, sort of. While dark chocolate contains some of the same compounds—fiber, oxalates—it has them in different forms, different ratios, and within a different food matrix, a different food ecosystem. We don't yet have the nutritional resolution or analytical tools to fully understand why different people react to different foods, and the foods themselves are complex. And that's the amazing, practical takeaway I'm really trying to share with you. We, as a society, love to reduce foods to isolated components—fiber, protein, fat, sugar, oxalates, phytates—but the complexity of the food-host interaction is beyond what most of us can imagine. And the only way to truly know how a food affects you is to test it. That is the N=1 scientific approach. And the great news? Access to self-testing is better than ever. You can get your own continuous glucose monitors over the counter, even without diabetes or prediabetes, and run these experiments on yourself if you're so inclined and you're curious. One company that offers this is Levels Health, and they have a great app that helps you track and interpret the data. I'll link to them, with a discount, yes, in the video notes if you want to try out a continuous glucose monitor for yourself. I find it really enlightening. Or if you want a broader view of your metabolic health, a company with which I'm affiliated, SiPhox, offers easy at-home testing kits with over 17 biomarkers. We're actually doing a metabolic health awareness promotion together, with no or minimal benefit to the company, honestly, thanks to a 50% discount on 2 kits. Like me, they believe in getting people's data in their own hands, empowering you to be the captain of your own health ship. Now, relevant and patient-empowering plugs aside, let me double down on the takeaway. The truth is, your body doesn't follow the guidelines. It follows you, your biology, your metabolism, your lived experience. So instead of relying on generic advice, start testing, start tracking, be curious about your own body, become your own scientist, collect your own data points. Because when it comes to your health, the most important lab, the most important test is you. Drop a comment and let me know what healthy food your body totally rebels against. In terms of blood sugar response or otherwise. I need to know I'm not the only one in the kale betrayal club. And if you found this video interesting and informative, hit the subscribe button just like kale hits my pancreas. You knew you weren't getting out of this one without a pun. I have a lot more unexpected, unusual, and hopefully informative lessons coming your way. Stay curious. Let me know if you enjoyed this one. Oh, and let me know what your favorite vegetable is.