17 Dec 2025 · 8 min
Brian Johnson breaks down David Ludwig's research on how fast-acting carbs like high-fructose corn syrup spike blood sugar and trigger the brain's reward center, increasing hunger and cravings. Swapping them for slow-acting starches and healthy fats can curb cravings and improve focus, even when calories stay the same.
Hey, this is Brian with a quick note before we jump into today's show. If you haven't signed up for the Optymyze Premium membership yet, A, what are you waiting for? And B, you can now get the first 30 days of optimizing for free. Just cruise on over to Optimize Me and sign up. Over 10,000 people now start their days with Optymyze so they can actualize their potential, including best selling authors, leading entrepreneurs and even NCAA championship teams. Two of them. So again, 30 days of free optimizing at Optimize Me. If you're already a member, thanks for your support. Now for the show, You're listening to Optimize with Brian Johnson. More wisdom in less time. Hi, this is Brian. Welcome back to another micro class. This one's on Conquer Cravings. It's inspired by Always Hungry. By David Ludwig, MD, PhD David Ludwig, MD, and PhD is a professor in both Harvard Medical School and Harvard's School of Public Health in the Department of Nutrition. Fascinating guy who's written over 100 peer reviewed academic journal articles and one of them was just. Many of them are fascinating that he shares in the book, but one of them was particularly just astonishing. Imagine this. And again, the intention here is to conquer cravings, which is the first intention of his three phase program. Imagine bringing people into your lab and offering them one of two different milkshakes, right? So half the group will get one milkshake, the other half will get the other milkshake. Short story here, half the group get fast acting corn syrup, fast acting carbs. This group gets slow corn starch, right? So fast acting carbs. Slow acting carbs. Group one, group two, as you may guess, group one's blood sugar went up faster than this group and higher than that group, but then it also dropped after three to four hours at a rate much lower than this group. Which establishes an important point, by the way, that not all calories are equal because these milkshakes were identical in total calorie and in distribution between fat, protein and carbohydrate. The only thing that was different and in sweetness, the only thing that was different was one had fast acting carbs and the other had slow acting carbs, right? So this group's blood sugar went up and then it went down. Their hunger went up. But here's what I found most fascinating. Then you take these people and you slide them into an FMRI machine. Hello, that's me going into. Or this person going into an FMRI machine. Now what would you expect to see in the Brain of these individuals. Anything different? Well, what they found was a part of the brain called the nucleus accumbens lit up just abs boop. He said it lit up like a laser. In every single one of the individuals who had the fast acting carbs, this part of their brain lit up, whereas it did not light up with the slow acting carbs. Now what we need to know about this part of the brain, the nucleus accumbens is it's known as the reward center, right? This is what's connected to addiction. So similar lights will fire, will light up in this area of the brain for individuals who are suffering from addiction, whether that's alcohol or cocaine, et cetera. So not only does our insulin get disrupted and our blood sugar gets disrupted with fast acting carbs, but we're actually lighting up our craving centers. Therefore, if you want to reduce your cravings and you need to reduce the number of fast acting carbs in your diet, David tells us the fastest way to do that is to eliminate this, reduce that and increase healthy fats. Which is what the book is all about, is talking about the science of why that's so powerful and what it does to change our metabolism. And paradoxically, eating more fat while eating less of the fast acting carbs helps you lose fat, helps you lose weight and get to a healthy, sustainable new weight set point. So that's a quick look at conquering cravings. This is a really, really powerful idea. Fast acting carbs, highly processed carbs, doesn't matter what nutritional philosophy you come from, no one is going to tell you to increase that in this guide. David Ludwig is the one who's actually connected it via his research to addiction centers. Keep that in mind as you go clean out your kitchen and get rid of all of your fast add acting carbs in there. We can have a very long conversation about this. In the note I talk about how this affects learning. So if you have kids in the house, well you, if you go out after eating fast acting carbs, you will not have as strong of a memory, as strong a focus that you want at work. And if you're giving it to your kids, he connects this to add like all this happens, all that happens. And with fast acting carbs, you can't maintain your attention and focus. You do that persistently over time and that starts looking like an ADD diagnosis. Again, we talk about it more in the note, he talks about it more in the book. But for now know that we want to reduce our fast acting carbs. Fastest way to conquer our cravings isn't it a bit odd that we went from math to science to history, but somehow missed the class on how to live. For some wacky reason, optimal living 101 never made the schedule. Of course, it's too late to go back and change that, and you're too busy to read full time to catch up yet. If you're like us, you're all about optimizing your life and actualizing your potential. So imagine this. Imagine having someone read the best books on optimal living and pulling out the big ideas that can truly change your life. You know those sections you asterisk and underline and mark all up? Then imagine that guy me connecting those ideas to other great books and helping you apply them to your life today. Well, that's what I do with something we call Philosopher's Notes where I break down each great book into a simple 6 page PDF, 20 minute MP3 and 10 minute Philosopher's Notes TV episode. Then imagine me taking the absolute best big ideas from those great books and sharing them with you in fun, inspiring, super practical optimal living 101 classes on stuff like purpose 101, confidence 101, business 101, meditation 101, that sort of thing. You've got a personal trainer? I'm kind of like your personal philosopher. Ancient Wisdom plus Modern Science plus Common Sense plus Virtue plus plus Mastery plus Fun. That's what our optimized membership program is all about. We'd love to have you join us. Check us out at BrianJohnson me join.
