Loved this piece! I'm going to ask this here because I keep searching for an answer: I see a lot of folks promoting white sugar (on its own or, like you said, in home made baked goods, with coffee, etc...) as a clean energy source for the body. On the other hand, I am inundated everywhere I turn with warnings about how inflammatory refined sugar is. I have RA, and am constantly told I need to cut out ALL refined sugar because it is so inflammatory. I'm having a lot of trouble squaring these two realities and feel like I'm missing some (maybe obvious??) piece of the puzzle. Thank you for any insight you could provide.
Great question, Siri, and the confusion is understandable because both camps are talking past each other. Let me try to untangle it.
The "sugar is inflammatory" claim almost always conflates three different things. First, refined sugar eaten in the context of seed oils, processed flour, and chronic stress isn't the same intervention as sugar eaten with a clean diet. Most studies showing sugar drives inflammation use participants already eating a high-PUFA inflammatory baseline diet. The sugar is the visible variable, but the seed oils are doing most of the damage. Sugar gets blamed because it's easier to identify than the seed oils saturating everything they eat.
Second, there's a difference between blood sugar spikes in someone with already-impaired glucose handling and clean glucose use in someone with healthy metabolism. If your cells can't burn glucose efficiently (because of chronic high free fatty acids in the blood, stored PUFA in cell membranes, hypothyroidism, chronic stress etc), then yes, eating sugar will leave glucose floating around in the blood doing damage. But the problem there isn't the sugar. It's the cellular dysfunction that prevents the cell from using glucose properly. Cutting sugar treats the symptom by removing the input. Restoring the cell's ability to burn glucose treats the actual problem.
Third, glucose itself is anti-stress at the physiological level. When the body has adequate glucose available, cortisol and adrenaline come down. When glucose is restricted, the body has to make its own through breaking down muscle, which requires elevated stress hormones running around the clock. Chronic stress hormone elevation drives autoimmune flares. So depending on how you're functioning metabolically, removing all sugar can keep you in a chronic stress state that makes the underlying inflammation worse.
I'll say this carefully because RA is personal for me too. I've been through it and I went into remission, but I learned the hard way that strict elimination of everything can suppress inflammation while costing you your hormonal balance, your cycles, and your nervous system.The deeper question is what's actually driving the inflammation, not which single ingredient to fear.
For RA specifically, I'd worry less about a teaspoon of sugar in your coffee or fruit with breakfast. I'd worry more about industrial seed oils (huge driver, hidden in almost everything processed), gut irritation from what you're eating, thyroid function, and chronic stress. These are the bigger levers. If your diet is otherwise clean and you're not running on stress hormones, modest amounts of sugar in good company (orange juice, fruit, honey, sugar in coffee) aren't your enemy.
I can't thank you enough for this detailed answer and I'm so grateful to have found your Substack. I'd love to hear more about your RA journey if/when that's something you'd like to share.
Organic cane sugar honey and well tolerated fruits.. home made chocolate milk with vanilla and cane sugar and whole milk pinch or two of kosher salt…my experience as a health coach is that arthritis is a low metabolic state and thyroid issue. Ray peat thoughts too. Eating a low oxalate diet and removing night shades bean nuts and other estrogenic foods like sweet potato and avoiding beta carotene… just some thoughts hope this helps
Thank you so much I appreciate this! It's funny because I'm also repeatedly told to cut out all dairy, especially milk, although I suspect this only has a big effect if you are already lactose intolerant/sensitive? I'm super interested in the Ray Peat approach but it runs counterintuitive to so many of the conventional wisdoms I'm being told... It's dang confusing.
I hear what you’re saying. If you are lactose intolerant, it could be also an energy problem. So one could start with maybe a quarter cup of milk or less gradually increasing day by day to tolerance. I suggested the chocolate milk with raw cacao which I could give you a recipe is helpful because I remember decades ago researching the cacao helps digest milk in people who have lactose issues and you could also buy lactose free milk which really does have the protective lactose. It just has the lactose enzyme added.
Yes, ray pears work is amazing and it changed my life. It might’ve even saved my life. I started studying his work in 2008 shortly after my daughter was born and I still played around with what I was programmed to believe about sugar it was a real tough one to let go of. What also helps is aspirin to mitigate the stored polyunsaturated fats in the tissue as well as vitamin E. If you are on telegram, Id be happy to exchange voice notes and assist in any way I can. Mike fave and jay feldman on YouTube are really great too.
Sure. Well, betacarotene can act, just like seed oils in regards, to metabolism and thyroid. When thyroid is lowered, estrogen goes up. When oestrogen goes up, thyroid goes down. Estrogen impairs the liver to convert inactive thyroid into active thyroid ( these are just brief explanations)Sweet potatoes in my opinion or one of the worst promoted health foods. They are so oxalate rich and filled with beta keratin that they can even cause some people to be nauseous and throw up because of their metabolic effects starting and effects on liver.
Pushing back on some of this because the claims don't hold up.
Beta carotene isn't like seed oils. Seed oils damage cells by oxidizing inside mitochondria. Beta carotene is an antioxidant. Totally different. Peat's real concern was just that hypothyroid people convert it to vitamin A poorly, so they accumulate it without getting the benefit.
Sweet potatoes aren't estrogenic. USDA puts raw sweet potato at 0.01 mg of isoflavones per 100g. Soy is 34.39. That's 3,400x more. Sweet potato is basically a rounding error.
They're also not "so oxalate rich." Roughly 19-50 mg per 100g. Spinach is 15-25x higher. Sweet potato is moderate at most. I think you meant beta carotene there, not beta keratin btw. Sweet potatoes have beta carotene (the orange pigment). Keratin is the protein in hair and nails.
And cooked sweet potatoes don't damage your liver. That's not a thing. Raw ones have some glycoalkaloids, sure. Allergies happen. Moldy ones are bad. But "metabolic effects on the liver causing vomiting" from eating a baked sweet potato isn't real.
This stuff matters because people stack food fears on top of each other and end up barely eating anything.
Ha, the spinach betrayal is real. The iron in spinach is barely absorbed anyway, partly because of polyphenols and calcium binding it up. Animal foods and vitamin C with your meal do way more for iron status than any leafy green
Really interesting and your take on this is more balanced than some I've seen on Substack. I'm curious as well, would this diet for few weeks work as a temporary 'clean out the system' that could then be eased into the fuller, long term healthy diet? I'm wondering if it could help people with decades of processed food abuse in their body feel a change quickly, because patience isn't a resource humanity has in abundance. Thanks for your post!
Probably not the way you'd hope, and it also depends a lot on what someone's actually dealing with. Approach for autoimmune is different from metabolic disease, which is different from someone just wanting to feel better after years of processed food. A few weeks of any restrictive diet feels good early because you're removing inflammatory inputs. But Kempner's deeper mechanism (clearing stored PUFA) doesn't really fire in a short window. PUFA half-life in body fat is years, not weeks. The other features of the diet (very low salt, low calcium, low protein, low fat) make it risky for a healthy person doing a "reset." Hyponatremia, thyroid suppression, muscle loss can show up fast. People mistake these for detox symptoms. For most people coming off years of processed food, what works better is simpler: stop eating seed oils and processed food. Eat real food including healthy carbs, salt to taste and be consistent with it.
This was so interesting. I remember hearing about the Rice Diet, but I did not know what it was based on. I'm also going to share with a friend who has Kidney problems.
This was a light bulb moment for me, a real understanding of the Randle Cycle and why the carnivore diet for me works so well. Thank you for sharing. 🙏😊👍
1) fruits and sugar don't have just glucose, but also fructose. Be careful with fructose if you have fatty liver and stuff.
2) How sure are you about the keto is that bad? Because there's pleeenty of anecdata from the keto community, even from people on long term (years) of keto, that they're doing well, but they eat a lot (so they don't starve themselves). I'd rather say that keto makes it easier to undereat, and that's what leads to the issues you mentioned.
3) Cortisol spikes in the mornings - are you saying we should ban mornings because they are stressful? :P My point being that cortisol is not the stress hormone, but a hormone that is (also) released in stress, but also at other times.
You’re missing the context the whole article is built on.
On fructose, the concern usually comes from studies where fructose is isolated, overfed, and combined with a high-fat background. That’s the environment where fructose is more likely to be pushed into fat storage. Kempner removed that environment. Fat intake was almost zero, which lowers circulating fatty acids and removes a major block on oxidation. In that state, carbohydrate is not driving fatty liver. It’s being used.
On keto, a lot of people coming into it are coming from unstable eating patterns, high seed oil intake, and constant blood sugar swings, so almost any structured approach will feel better at first. But keto “working” short term doesn’t mean it’s restoring normal physiology. Your brain alone requires roughly 100–120 grams of glucose per day. If you don’t eat carbs, the body has to make glucose internally through gluconeogenesis. That process relies heavily on amino acids, which means ongoing tissue breakdown, and it’s supported by cortisol and adrenaline. So you’re maintaining blood sugar by running a stress-driven process in the background.
At the same time, low carbohydrate intake means low liver glycogen. Adequate glycogen supports the conversion of T4 to active T3. When glycogen stays low, that conversion tends to drop. Thyroid output effectively downshifts, metabolic rate falls, and you start seeing the pattern many long-term keto people report: cold hands and feet, fatigue, constipation, hair thinning, poor sleep, anxiety. In women, it often shows up as disrupted cycles.
Blood glucose can still look normal on labs because the body is forcing it to stay normal. That’s the point of the compensation. But normal glucose maintained by stress hormones and tissue breakdown is not the same as normal glucose from proper fuel use.
So yes, people can feel good initially. But the mechanism underneath is compensatory, not restorative, and over time that distinction starts to show.
3. On cortisol, of course it’s not “the bad hormone.” It has a normal rhythm and a clear role, including the morning rise. The issue is whether it’s acting within that rhythm or being chronically elevated to sustain processes like continuous gluconeogenesis
These were people with malignant hypertension. The diet was designed to address the malignant hypertension. It did that dramatically. The reversals that he saw in many organs were largely as a result of reduced blood pressure.
The diet wasn't designed for malignant hypertension. Kempner designed it for kidney disease based on his cellular metabolism research from his time in Otto Warburg's lab. The BP improvements were noticed along the way in kidney patients who also had hypertension. The diabetes work came years later and surprised him because conventional wisdom said high carbs would worsen diabetes. He went ahead anyway because his metabolic framework predicted it would help, and it did. So the diet was metabolic from the start, with hypertension as one of several conditions it ended up reversing, not the original target. Besides, if lowering BP alone explained Kempner's results, modern antihypertensive drugs should produce the same outcomes. They don't. Patients on BP medications control their numbers but don't show reversal of diabetic retinopathy, kidney recovery, or the cholesterol drops Kempner documented at the rates he saw. Something else was happening. The diabetic patients are the clearest example. Their fasting glucose dropped and insulin requirements fell on a 90% carb diet.
Loved this piece! I'm going to ask this here because I keep searching for an answer: I see a lot of folks promoting white sugar (on its own or, like you said, in home made baked goods, with coffee, etc...) as a clean energy source for the body. On the other hand, I am inundated everywhere I turn with warnings about how inflammatory refined sugar is. I have RA, and am constantly told I need to cut out ALL refined sugar because it is so inflammatory. I'm having a lot of trouble squaring these two realities and feel like I'm missing some (maybe obvious??) piece of the puzzle. Thank you for any insight you could provide.
Great question, Siri, and the confusion is understandable because both camps are talking past each other. Let me try to untangle it.
The "sugar is inflammatory" claim almost always conflates three different things. First, refined sugar eaten in the context of seed oils, processed flour, and chronic stress isn't the same intervention as sugar eaten with a clean diet. Most studies showing sugar drives inflammation use participants already eating a high-PUFA inflammatory baseline diet. The sugar is the visible variable, but the seed oils are doing most of the damage. Sugar gets blamed because it's easier to identify than the seed oils saturating everything they eat.
Second, there's a difference between blood sugar spikes in someone with already-impaired glucose handling and clean glucose use in someone with healthy metabolism. If your cells can't burn glucose efficiently (because of chronic high free fatty acids in the blood, stored PUFA in cell membranes, hypothyroidism, chronic stress etc), then yes, eating sugar will leave glucose floating around in the blood doing damage. But the problem there isn't the sugar. It's the cellular dysfunction that prevents the cell from using glucose properly. Cutting sugar treats the symptom by removing the input. Restoring the cell's ability to burn glucose treats the actual problem.
Third, glucose itself is anti-stress at the physiological level. When the body has adequate glucose available, cortisol and adrenaline come down. When glucose is restricted, the body has to make its own through breaking down muscle, which requires elevated stress hormones running around the clock. Chronic stress hormone elevation drives autoimmune flares. So depending on how you're functioning metabolically, removing all sugar can keep you in a chronic stress state that makes the underlying inflammation worse.
I'll say this carefully because RA is personal for me too. I've been through it and I went into remission, but I learned the hard way that strict elimination of everything can suppress inflammation while costing you your hormonal balance, your cycles, and your nervous system.The deeper question is what's actually driving the inflammation, not which single ingredient to fear.
For RA specifically, I'd worry less about a teaspoon of sugar in your coffee or fruit with breakfast. I'd worry more about industrial seed oils (huge driver, hidden in almost everything processed), gut irritation from what you're eating, thyroid function, and chronic stress. These are the bigger levers. If your diet is otherwise clean and you're not running on stress hormones, modest amounts of sugar in good company (orange juice, fruit, honey, sugar in coffee) aren't your enemy.
I can't thank you enough for this detailed answer and I'm so grateful to have found your Substack. I'd love to hear more about your RA journey if/when that's something you'd like to share.
Organic cane sugar honey and well tolerated fruits.. home made chocolate milk with vanilla and cane sugar and whole milk pinch or two of kosher salt…my experience as a health coach is that arthritis is a low metabolic state and thyroid issue. Ray peat thoughts too. Eating a low oxalate diet and removing night shades bean nuts and other estrogenic foods like sweet potato and avoiding beta carotene… just some thoughts hope this helps
Thank you so much I appreciate this! It's funny because I'm also repeatedly told to cut out all dairy, especially milk, although I suspect this only has a big effect if you are already lactose intolerant/sensitive? I'm super interested in the Ray Peat approach but it runs counterintuitive to so many of the conventional wisdoms I'm being told... It's dang confusing.
I hear what you’re saying. If you are lactose intolerant, it could be also an energy problem. So one could start with maybe a quarter cup of milk or less gradually increasing day by day to tolerance. I suggested the chocolate milk with raw cacao which I could give you a recipe is helpful because I remember decades ago researching the cacao helps digest milk in people who have lactose issues and you could also buy lactose free milk which really does have the protective lactose. It just has the lactose enzyme added.
Yes, ray pears work is amazing and it changed my life. It might’ve even saved my life. I started studying his work in 2008 shortly after my daughter was born and I still played around with what I was programmed to believe about sugar it was a real tough one to let go of. What also helps is aspirin to mitigate the stored polyunsaturated fats in the tissue as well as vitamin E. If you are on telegram, Id be happy to exchange voice notes and assist in any way I can. Mike fave and jay feldman on YouTube are really great too.
Important to buy cacao powder from soil low in cadmium (and lead?) I’ve read that West Africa and the Caribbean are good sources.
That is so generous <3 I am on Telegram as @sathorson, I would love to chat there.
Sweet potatoes are estrogenic? What’s the problem with beta-carotene? Could you please elaborate 🙏🏼
Sure. Well, betacarotene can act, just like seed oils in regards, to metabolism and thyroid. When thyroid is lowered, estrogen goes up. When oestrogen goes up, thyroid goes down. Estrogen impairs the liver to convert inactive thyroid into active thyroid ( these are just brief explanations)Sweet potatoes in my opinion or one of the worst promoted health foods. They are so oxalate rich and filled with beta keratin that they can even cause some people to be nauseous and throw up because of their metabolic effects starting and effects on liver.
Pushing back on some of this because the claims don't hold up.
Beta carotene isn't like seed oils. Seed oils damage cells by oxidizing inside mitochondria. Beta carotene is an antioxidant. Totally different. Peat's real concern was just that hypothyroid people convert it to vitamin A poorly, so they accumulate it without getting the benefit.
Sweet potatoes aren't estrogenic. USDA puts raw sweet potato at 0.01 mg of isoflavones per 100g. Soy is 34.39. That's 3,400x more. Sweet potato is basically a rounding error.
They're also not "so oxalate rich." Roughly 19-50 mg per 100g. Spinach is 15-25x higher. Sweet potato is moderate at most. I think you meant beta carotene there, not beta keratin btw. Sweet potatoes have beta carotene (the orange pigment). Keratin is the protein in hair and nails.
And cooked sweet potatoes don't damage your liver. That's not a thing. Raw ones have some glycoalkaloids, sure. Allergies happen. Moldy ones are bad. But "metabolic effects on the liver causing vomiting" from eating a baked sweet potato isn't real.
This stuff matters because people stack food fears on top of each other and end up barely eating anything.
Thanks for clarification on oxalate levels as an anemic girlie it matters. I was real mad when I found out about spinach. 😅
Ha, the spinach betrayal is real. The iron in spinach is barely absorbed anyway, partly because of polyphenols and calcium binding it up. Animal foods and vitamin C with your meal do way more for iron status than any leafy green
Thanks for enlarging my perceptions! That was one of the strangest diets I’ve read about. I wonder how they ate the sugar and was it plain white?
Really interesting and your take on this is more balanced than some I've seen on Substack. I'm curious as well, would this diet for few weeks work as a temporary 'clean out the system' that could then be eased into the fuller, long term healthy diet? I'm wondering if it could help people with decades of processed food abuse in their body feel a change quickly, because patience isn't a resource humanity has in abundance. Thanks for your post!
Probably not the way you'd hope, and it also depends a lot on what someone's actually dealing with. Approach for autoimmune is different from metabolic disease, which is different from someone just wanting to feel better after years of processed food. A few weeks of any restrictive diet feels good early because you're removing inflammatory inputs. But Kempner's deeper mechanism (clearing stored PUFA) doesn't really fire in a short window. PUFA half-life in body fat is years, not weeks. The other features of the diet (very low salt, low calcium, low protein, low fat) make it risky for a healthy person doing a "reset." Hyponatremia, thyroid suppression, muscle loss can show up fast. People mistake these for detox symptoms. For most people coming off years of processed food, what works better is simpler: stop eating seed oils and processed food. Eat real food including healthy carbs, salt to taste and be consistent with it.
Super interesting, thanks!
🙏🏻
This was so interesting. I remember hearing about the Rice Diet, but I did not know what it was based on. I'm also going to share with a friend who has Kidney problems.
This was a light bulb moment for me, a real understanding of the Randle Cycle and why the carnivore diet for me works so well. Thank you for sharing. 🙏😊👍
1) fruits and sugar don't have just glucose, but also fructose. Be careful with fructose if you have fatty liver and stuff.
2) How sure are you about the keto is that bad? Because there's pleeenty of anecdata from the keto community, even from people on long term (years) of keto, that they're doing well, but they eat a lot (so they don't starve themselves). I'd rather say that keto makes it easier to undereat, and that's what leads to the issues you mentioned.
3) Cortisol spikes in the mornings - are you saying we should ban mornings because they are stressful? :P My point being that cortisol is not the stress hormone, but a hormone that is (also) released in stress, but also at other times.
You’re missing the context the whole article is built on.
On fructose, the concern usually comes from studies where fructose is isolated, overfed, and combined with a high-fat background. That’s the environment where fructose is more likely to be pushed into fat storage. Kempner removed that environment. Fat intake was almost zero, which lowers circulating fatty acids and removes a major block on oxidation. In that state, carbohydrate is not driving fatty liver. It’s being used.
On keto, a lot of people coming into it are coming from unstable eating patterns, high seed oil intake, and constant blood sugar swings, so almost any structured approach will feel better at first. But keto “working” short term doesn’t mean it’s restoring normal physiology. Your brain alone requires roughly 100–120 grams of glucose per day. If you don’t eat carbs, the body has to make glucose internally through gluconeogenesis. That process relies heavily on amino acids, which means ongoing tissue breakdown, and it’s supported by cortisol and adrenaline. So you’re maintaining blood sugar by running a stress-driven process in the background.
At the same time, low carbohydrate intake means low liver glycogen. Adequate glycogen supports the conversion of T4 to active T3. When glycogen stays low, that conversion tends to drop. Thyroid output effectively downshifts, metabolic rate falls, and you start seeing the pattern many long-term keto people report: cold hands and feet, fatigue, constipation, hair thinning, poor sleep, anxiety. In women, it often shows up as disrupted cycles.
Blood glucose can still look normal on labs because the body is forcing it to stay normal. That’s the point of the compensation. But normal glucose maintained by stress hormones and tissue breakdown is not the same as normal glucose from proper fuel use.
So yes, people can feel good initially. But the mechanism underneath is compensatory, not restorative, and over time that distinction starts to show.
3. On cortisol, of course it’s not “the bad hormone.” It has a normal rhythm and a clear role, including the morning rise. The issue is whether it’s acting within that rhythm or being chronically elevated to sustain processes like continuous gluconeogenesis
These were people with malignant hypertension. The diet was designed to address the malignant hypertension. It did that dramatically. The reversals that he saw in many organs were largely as a result of reduced blood pressure.
The diet wasn't designed for malignant hypertension. Kempner designed it for kidney disease based on his cellular metabolism research from his time in Otto Warburg's lab. The BP improvements were noticed along the way in kidney patients who also had hypertension. The diabetes work came years later and surprised him because conventional wisdom said high carbs would worsen diabetes. He went ahead anyway because his metabolic framework predicted it would help, and it did. So the diet was metabolic from the start, with hypertension as one of several conditions it ended up reversing, not the original target. Besides, if lowering BP alone explained Kempner's results, modern antihypertensive drugs should produce the same outcomes. They don't. Patients on BP medications control their numbers but don't show reversal of diabetic retinopathy, kidney recovery, or the cholesterol drops Kempner documented at the rates he saw. Something else was happening. The diabetic patients are the clearest example. Their fasting glucose dropped and insulin requirements fell on a 90% carb diet.