David Ludwig MD, PhD
@davidludwigmd.bsky.social
Endocrinologist, Nutrition Researcher, Public Health Advocate. #1 NYT bestselling author of Always Hungry? and cookbook Always Delicious.
Pinned
The notion of "ultra-processed" food is so complicated, not even @fda.gov knows how to define it.
There's a simpler way. Focus on the main health offenders:
👉Refined grains, sugar, and other highly processed carbs.
In print today.
Free online access (requires email) wapo.st/3WuPHGJ
There's a simpler way. Focus on the main health offenders:
👉Refined grains, sugar, and other highly processed carbs.
In print today.
Free online access (requires email) wapo.st/3WuPHGJ
LOW-CARB DIETS
Start of my career: "They don't work for wt loss"
Then: "You'll be a lean corpse"
Now: versus higher carb, IMPROVED
* Body comp
* BP
* TG
* VLDL
* ApoB-A1 ratio
* endothelial markers
* inflam markers
* overall CVD risk
(yes, LDL goes)
www.sciencedirect.com/science/arti...
Start of my career: "They don't work for wt loss"
Then: "You'll be a lean corpse"
Now: versus higher carb, IMPROVED
* Body comp
* BP
* TG
* VLDL
* ApoB-A1 ratio
* endothelial markers
* inflam markers
* overall CVD risk
(yes, LDL goes)
www.sciencedirect.com/science/arti...
Effects of carbohydrate-restricted diets and macronutrient replacements on cardiovascular health and body composition in adults: a meta-analysis of randomized trials
Carbohydrate-restricted diets (CRDs) are widely promoted for improving cardiovascular and body composition outcomes, yet evidence remains mixed across…
www.sciencedirect.com
November 21, 2025 at 1:53 PM
LOW-CARB DIETS
Start of my career: "They don't work for wt loss"
Then: "You'll be a lean corpse"
Now: versus higher carb, IMPROVED
* Body comp
* BP
* TG
* VLDL
* ApoB-A1 ratio
* endothelial markers
* inflam markers
* overall CVD risk
(yes, LDL goes)
www.sciencedirect.com/science/arti...
Start of my career: "They don't work for wt loss"
Then: "You'll be a lean corpse"
Now: versus higher carb, IMPROVED
* Body comp
* BP
* TG
* VLDL
* ApoB-A1 ratio
* endothelial markers
* inflam markers
* overall CVD risk
(yes, LDL goes)
www.sciencedirect.com/science/arti...
Adults (average BMI 25) ate:
2 cups fruit daily or none for 8 wk
(8-wk "washout period" - pretty good, all considered)
Fruit (including bananas, apples, oranges, watermelon)
👉 ⬆️ some blood nutrients
👉BUT insulin resistance better without the fruit
cdn.nutrition.org/article/S247...
2 cups fruit daily or none for 8 wk
(8-wk "washout period" - pretty good, all considered)
Fruit (including bananas, apples, oranges, watermelon)
👉 ⬆️ some blood nutrients
👉BUT insulin resistance better without the fruit
cdn.nutrition.org/article/S247...
October 14, 2025 at 11:39 AM
Adults (average BMI 25) ate:
2 cups fruit daily or none for 8 wk
(8-wk "washout period" - pretty good, all considered)
Fruit (including bananas, apples, oranges, watermelon)
👉 ⬆️ some blood nutrients
👉BUT insulin resistance better without the fruit
cdn.nutrition.org/article/S247...
2 cups fruit daily or none for 8 wk
(8-wk "washout period" - pretty good, all considered)
Fruit (including bananas, apples, oranges, watermelon)
👉 ⬆️ some blood nutrients
👉BUT insulin resistance better without the fruit
cdn.nutrition.org/article/S247...
The notion of "ultra-processed" food is so complicated, not even @fda.gov knows how to define it.
There's a simpler way. Focus on the main health offenders:
👉Refined grains, sugar, and other highly processed carbs.
In print today.
Free online access (requires email) wapo.st/3WuPHGJ
There's a simpler way. Focus on the main health offenders:
👉Refined grains, sugar, and other highly processed carbs.
In print today.
Free online access (requires email) wapo.st/3WuPHGJ
October 13, 2025 at 9:05 AM
The notion of "ultra-processed" food is so complicated, not even @fda.gov knows how to define it.
There's a simpler way. Focus on the main health offenders:
👉Refined grains, sugar, and other highly processed carbs.
In print today.
Free online access (requires email) wapo.st/3WuPHGJ
There's a simpler way. Focus on the main health offenders:
👉Refined grains, sugar, and other highly processed carbs.
In print today.
Free online access (requires email) wapo.st/3WuPHGJ
Will targeting "ultra-processed food" in national nutrition policy make Americans (and the rest of the world) healthier?
I argue there is a better way
wapo.st/3WuPHGJ
I argue there is a better way
wapo.st/3WuPHGJ
Opinion | Targeting ultra-processed food repeats America’s missteps on nutrition
MAHA blames this food group for chronic disease. Nutrition science isn’t so simple.
wapo.st
October 6, 2025 at 10:27 AM
Will targeting "ultra-processed food" in national nutrition policy make Americans (and the rest of the world) healthier?
I argue there is a better way
wapo.st/3WuPHGJ
I argue there is a better way
wapo.st/3WuPHGJ
Reposted by David Ludwig MD, PhD
In @natmed.nature.com, Mary Putt (@dbei-upenn.bsky.social), @davidludwigmd.bsky.social & Walter Willett (@hsph.harvard.edu) discuss concerns for the validity of short-term dietary crossover trials www.nature.com/articles/s41...
September 26, 2025 at 5:20 PM
In @natmed.nature.com, Mary Putt (@dbei-upenn.bsky.social), @davidludwigmd.bsky.social & Walter Willett (@hsph.harvard.edu) discuss concerns for the validity of short-term dietary crossover trials www.nature.com/articles/s41...
Target "ultra-processed foods" to tackle the chronic disease epidemic .... What could possibly go wrong? My 50 min convo with Nick Norwitz www.youtube.com/watch?v=JAPg...
This Will Change Your Mind on Ultra-Processed Foods (Harvard MD PhDs Discuss)
YouTube video by Nick Norwitz
www.youtube.com
September 17, 2025 at 6:32 PM
Target "ultra-processed foods" to tackle the chronic disease epidemic .... What could possibly go wrong? My 50 min convo with Nick Norwitz www.youtube.com/watch?v=JAPg...
When you have 50 min ...
The investigative journalist Gary Taubes and I discuss the notion of ultra-processed foods, the sorry state of nutrition research ... and how we can inch toward truth when scientific paradigms collide.
www.youtube.com/watch?v=PfOb...
The investigative journalist Gary Taubes and I discuss the notion of ultra-processed foods, the sorry state of nutrition research ... and how we can inch toward truth when scientific paradigms collide.
www.youtube.com/watch?v=PfOb...
The Ultra-Processed Food Debate: Science, Bias, & Truth
YouTube video by Metabolic Mind
www.youtube.com
September 10, 2025 at 2:46 PM
When you have 50 min ...
The investigative journalist Gary Taubes and I discuss the notion of ultra-processed foods, the sorry state of nutrition research ... and how we can inch toward truth when scientific paradigms collide.
www.youtube.com/watch?v=PfOb...
The investigative journalist Gary Taubes and I discuss the notion of ultra-processed foods, the sorry state of nutrition research ... and how we can inch toward truth when scientific paradigms collide.
www.youtube.com/watch?v=PfOb...
The hotter it gets, the more sugar we consume ... mainly in the form of sugary drinks.
👉Let's find other ways to keep cool
www.nature.com/articles/s41...
👉Let's find other ways to keep cool
www.nature.com/articles/s41...
Rising temperatures increase added sugar intake disproportionately in disadvantaged groups in the USA - Nature Climate Change
Few studies have evaluated how climate change may affect dietary habits and nutritional health. Here, using transaction data in the USA, the authors show that added sugar consumption increases with te...
www.nature.com
September 9, 2025 at 1:08 PM
The hotter it gets, the more sugar we consume ... mainly in the form of sugary drinks.
👉Let's find other ways to keep cool
www.nature.com/articles/s41...
👉Let's find other ways to keep cool
www.nature.com/articles/s41...
Should national nutrition policy target "Ultra-Processed Foods" as many advocate?
I consider concerns in @nejm.org
Like 'The Emperor's New Clothes'
👉We're rolling out a red carpet, but the evidence is threadbare!
NEJM: www.nejm.org/doi/10.1056/...
BLOG (no paywall) medium.com/@davidludwig...
I consider concerns in @nejm.org
Like 'The Emperor's New Clothes'
👉We're rolling out a red carpet, but the evidence is threadbare!
NEJM: www.nejm.org/doi/10.1056/...
BLOG (no paywall) medium.com/@davidludwig...
Ultraprocessed Food on an Ultrafast Track | NEJM
The Nova food-classification system has advanced efforts to address modern diets of
highly processed foods. But it’s unclear whether it can be codified at a national
level to support public health.
www.nejm.org
September 4, 2025 at 7:46 PM
Should national nutrition policy target "Ultra-Processed Foods" as many advocate?
I consider concerns in @nejm.org
Like 'The Emperor's New Clothes'
👉We're rolling out a red carpet, but the evidence is threadbare!
NEJM: www.nejm.org/doi/10.1056/...
BLOG (no paywall) medium.com/@davidludwig...
I consider concerns in @nejm.org
Like 'The Emperor's New Clothes'
👉We're rolling out a red carpet, but the evidence is threadbare!
NEJM: www.nejm.org/doi/10.1056/...
BLOG (no paywall) medium.com/@davidludwig...
Certified for 1-oar rowing today in Hellerup, Denmark (where we live part time).
I don't believe I have Viking ancestors, but if I do, they would be proud. 😀
I don't believe I have Viking ancestors, but if I do, they would be proud. 😀
June 7, 2025 at 1:50 PM
Certified for 1-oar rowing today in Hellerup, Denmark (where we live part time).
I don't believe I have Viking ancestors, but if I do, they would be proud. 😀
I don't believe I have Viking ancestors, but if I do, they would be proud. 😀
My 1-hour (40 min on 1.5 x 😀) deep dive on the diets, nutrition research, and where we go from here ... with journalist Gary Taubes, hosted by @metabolicmind.bsky.social
The Truth About Nutrition Science: Is The Government Getting it Wrong?
YouTube video by Metabolic Mind
www.youtube.com
June 5, 2025 at 2:09 PM
My 1-hour (40 min on 1.5 x 😀) deep dive on the diets, nutrition research, and where we go from here ... with journalist Gary Taubes, hosted by @metabolicmind.bsky.social
Debating the Carbohydrate-Insulin Model with John Speakman in Cell Metabolism.
Letter-to-the-Editor (open access) authors.elsevier.com/a/1lCYr5WXUl...
Reply www.cell.com/cell-metabol...
Letter-to-the-Editor (open access) authors.elsevier.com/a/1lCYr5WXUl...
Reply www.cell.com/cell-metabol...
June 3, 2025 at 5:05 PM
Debating the Carbohydrate-Insulin Model with John Speakman in Cell Metabolism.
Letter-to-the-Editor (open access) authors.elsevier.com/a/1lCYr5WXUl...
Reply www.cell.com/cell-metabol...
Letter-to-the-Editor (open access) authors.elsevier.com/a/1lCYr5WXUl...
Reply www.cell.com/cell-metabol...
Avoid carbs to prevent malaria?
Preliminary evidence suggests maybe so ...
www.nature.com/articles/s42...
Preliminary evidence suggests maybe so ...
www.nature.com/articles/s42...
β-hydroxybutyrate inhibits Plasmodium falciparum development and confers protection against malaria in mice - Nature Metabolism
A ketogenic diet and the ketone body β-hydroxybutyrate are shown to confer resistance to malaria in mice by inducing metabolic reprogramming in Plasmodium parasites, suggesting a dietary strategy for ...
www.nature.com
May 26, 2025 at 12:36 PM
Avoid carbs to prevent malaria?
Preliminary evidence suggests maybe so ...
www.nature.com/articles/s42...
Preliminary evidence suggests maybe so ...
www.nature.com/articles/s42...
“Pathological” science?
To solve the chronic disease epidemics, we need to get the research right.
Gary Taubes on the failure of nutrition science to correct fatally flawed diet trials … and avoid these blunders in the first place.
To solve the chronic disease epidemics, we need to get the research right.
Gary Taubes on the failure of nutrition science to correct fatally flawed diet trials … and avoid these blunders in the first place.
NIH Has A Nutrition Problem (Part 2 )
If you want to demonstrate that a plant-based diet is better than a ketogenic diet (or that ultra-processed food makes us overeat), these critical design flaws will help
substack.com
May 25, 2025 at 2:49 PM
“Pathological” science?
To solve the chronic disease epidemics, we need to get the research right.
Gary Taubes on the failure of nutrition science to correct fatally flawed diet trials … and avoid these blunders in the first place.
To solve the chronic disease epidemics, we need to get the research right.
Gary Taubes on the failure of nutrition science to correct fatally flawed diet trials … and avoid these blunders in the first place.
Italian professional societies consensus report on diet and skin disease.
Data are preliminary but promising:
👉Low-carb ketogenic diet may help acne, psoriasis
link.springer.com/article/10.1...
Data are preliminary but promising:
👉Low-carb ketogenic diet may help acne, psoriasis
link.springer.com/article/10.1...
Medical Nutrition Therapy in Dermatological Diseases: A Joint Consensus Statement of the Italian Association of Dietetics and Clinical Nutrition (ADI), the Italian Society of Dermatology and Sexually ...
Summary Dermatological diseases such as acne, hidradenitis suppurativa (HS), and psoriasis are driven by chronic inflammation and oxidative stress. Emerging evidence highlights the role of nutrition i...
link.springer.com
May 19, 2025 at 12:17 PM
Italian professional societies consensus report on diet and skin disease.
Data are preliminary but promising:
👉Low-carb ketogenic diet may help acne, psoriasis
link.springer.com/article/10.1...
Data are preliminary but promising:
👉Low-carb ketogenic diet may help acne, psoriasis
link.springer.com/article/10.1...
NIH Nutrition Research Takes it on the Chin
Gary Taubes' deep dive into the largest nutrition trial in years.
#DesignedToFail
uncertaintyprinciples.substack.com/p/nih-nutrit...
Gary Taubes' deep dive into the largest nutrition trial in years.
#DesignedToFail
uncertaintyprinciples.substack.com/p/nih-nutrit...
NIH Nutrition Research Takes it on the Chin
A "top" nutrition researcher exits, followed by two damning articles challenging his studies and claiming that a flagship $170 million NIH initiative is "designed to fail."
uncertaintyprinciples.substack.com
May 14, 2025 at 8:08 PM
NIH Nutrition Research Takes it on the Chin
Gary Taubes' deep dive into the largest nutrition trial in years.
#DesignedToFail
uncertaintyprinciples.substack.com/p/nih-nutrit...
Gary Taubes' deep dive into the largest nutrition trial in years.
#DesignedToFail
uncertaintyprinciples.substack.com/p/nih-nutrit...
Reposted by David Ludwig MD, PhD
What diet works best to prevent obesity, diabetes, cardiovascular disease, cancer and Alzheimer’s? Answers remain elusive...But why? The problem may be rooted in poorly designed nutrition research. @davidludwigmd.bsky.social chibe.upenn.edu/news/short-t...
Short-term diet trials are designed to fail - Center for Health Incentives and Behavioral Economics (CHIBE)
This article critiques short-term diet trials, arguing they are inadequate for understanding nutrition's impact on chronic disease.
chibe.upenn.edu
May 12, 2025 at 7:57 PM
What diet works best to prevent obesity, diabetes, cardiovascular disease, cancer and Alzheimer’s? Answers remain elusive...But why? The problem may be rooted in poorly designed nutrition research. @davidludwigmd.bsky.social chibe.upenn.edu/news/short-t...
Reposted by David Ludwig MD, PhD
Designed to Fail:
Why short-term diet trials cannot solve the epidemics of chronic disease.
👉New blog post (no paywall)
Why short-term diet trials cannot solve the epidemics of chronic disease.
👉New blog post (no paywall)
Designed to Fail: Why Short-term Diet Trials Cannot Solve the Epidemics of Chronic Disease
A version of this essay was published in STAT News First Opinion on April 22
davidludwigmd.medium.com
April 27, 2025 at 12:44 PM
Designed to Fail:
Why short-term diet trials cannot solve the epidemics of chronic disease.
👉New blog post (no paywall)
Why short-term diet trials cannot solve the epidemics of chronic disease.
👉New blog post (no paywall)
Reposted by David Ludwig MD, PhD
The effects of an intervention may take time to develop and persist after discontinuation, producing wash-in and washout effects that threaten trial validity.
This article describes the nature of this bias in nutrition research as an illustrative case
www.bmj.com/content/389/...
This article describes the nature of this bias in nutrition research as an illustrative case
www.bmj.com/content/389/...
April 30, 2025 at 4:47 PM
The effects of an intervention may take time to develop and persist after discontinuation, producing wash-in and washout effects that threaten trial validity.
This article describes the nature of this bias in nutrition research as an illustrative case
www.bmj.com/content/389/...
This article describes the nature of this bias in nutrition research as an illustrative case
www.bmj.com/content/389/...
Reposted by David Ludwig MD, PhD
In an associated opinion piece in STAT News (www.statnews.com/2025/04/22/n...),
Short-term diet trials are designed to fail
Does ultra-processed food cause obesity? Maybe, but we’ll never know from short-term trials.
www.statnews.com
April 28, 2025 at 3:23 PM
In an associated opinion piece in STAT News (www.statnews.com/2025/04/22/n...),
Designed to Fail:
Why short-term diet trials cannot solve the epidemics of chronic disease.
👉New blog post (no paywall)
Why short-term diet trials cannot solve the epidemics of chronic disease.
👉New blog post (no paywall)
Designed to Fail: Why Short-term Diet Trials Cannot Solve the Epidemics of Chronic Disease
A version of this essay was published in STAT News First Opinion on April 22
davidludwigmd.medium.com
April 27, 2025 at 12:44 PM
Designed to Fail:
Why short-term diet trials cannot solve the epidemics of chronic disease.
👉New blog post (no paywall)
Why short-term diet trials cannot solve the epidemics of chronic disease.
👉New blog post (no paywall)
Designed to Fail
Why short-term trials, like those in the $170M Nutrition for Precision Health initiative, cannot solve the epidemics of chronic disease.
Study in BMJ with Walt Willett and Mary Putt www.bmj.com/content/389/...
Opinion in @statnews.com
www.statnews.com/2025/04/22/n...
Why short-term trials, like those in the $170M Nutrition for Precision Health initiative, cannot solve the epidemics of chronic disease.
Study in BMJ with Walt Willett and Mary Putt www.bmj.com/content/389/...
Opinion in @statnews.com
www.statnews.com/2025/04/22/n...
Wash-in and washout effects: mitigating bias in short term dietary and other trials
Short term trials with surrogate measures instead of hard outcomes are often used to study chronic diseases. The effects of an intervention may, however, take time to develop and persist after discont...
www.bmj.com
April 22, 2025 at 9:22 AM
Designed to Fail
Why short-term trials, like those in the $170M Nutrition for Precision Health initiative, cannot solve the epidemics of chronic disease.
Study in BMJ with Walt Willett and Mary Putt www.bmj.com/content/389/...
Opinion in @statnews.com
www.statnews.com/2025/04/22/n...
Why short-term trials, like those in the $170M Nutrition for Precision Health initiative, cannot solve the epidemics of chronic disease.
Study in BMJ with Walt Willett and Mary Putt www.bmj.com/content/389/...
Opinion in @statnews.com
www.statnews.com/2025/04/22/n...
Fascinating review cancer cell metabolism.
Most cancer treatments harm the "host" (ie, the patient), in addition to the tumor.
With knowledge of metabolism, we might be able to:
👉Attack the tumor AND
👉Support the host
Most cancer treatments harm the "host" (ie, the patient), in addition to the tumor.
With knowledge of metabolism, we might be able to:
👉Attack the tumor AND
👉Support the host
Tumor metabolism as a factor affecting diversity in cancer cachexia | American Journal of Physiology-Cell Physiology | American Physiological Society
Cancer cachexia is a multifaceted metabolic syndrome characterized by muscle wasting, fat redistribution, and metabolic dysregulation, commonly associated with advanced cancer but sometimes also evide...
journals.physiology.org
April 3, 2025 at 1:29 PM
Fascinating review cancer cell metabolism.
Most cancer treatments harm the "host" (ie, the patient), in addition to the tumor.
With knowledge of metabolism, we might be able to:
👉Attack the tumor AND
👉Support the host
Most cancer treatments harm the "host" (ie, the patient), in addition to the tumor.
With knowledge of metabolism, we might be able to:
👉Attack the tumor AND
👉Support the host
Important paper on risk factors and life expectancy worldwide.
Action mostly with smoking, diabetes, BP, weight. Less so with LDL chol.
(Probably written by a committee: 👉"modification of smoking ... was associated with the most additional life-years free of death")
www.nejm.org/doi/abs/10.1...
Action mostly with smoking, diabetes, BP, weight. Less so with LDL chol.
(Probably written by a committee: 👉"modification of smoking ... was associated with the most additional life-years free of death")
www.nejm.org/doi/abs/10.1...
Global Effect of Cardiovascular Risk Factors on Lifetime Estimates | NEJM
Five risk factors account for approximately 50% of the global burden of cardiovascular
disease. How the presence or absence of classic risk factors affects lifetime estimates
of cardiovascular dise...
www.nejm.org
April 2, 2025 at 11:39 AM
Important paper on risk factors and life expectancy worldwide.
Action mostly with smoking, diabetes, BP, weight. Less so with LDL chol.
(Probably written by a committee: 👉"modification of smoking ... was associated with the most additional life-years free of death")
www.nejm.org/doi/abs/10.1...
Action mostly with smoking, diabetes, BP, weight. Less so with LDL chol.
(Probably written by a committee: 👉"modification of smoking ... was associated with the most additional life-years free of death")
www.nejm.org/doi/abs/10.1...
Reposted by David Ludwig MD, PhD
“Infants may consume upwards of 60 grams of added sugars per day, or the equivalent of two soft drinks per day if they are entirely formula-fed,” researchers say in the study, published yesterday [Feb. 24, 2025] in the Journal of Food Composition and Analysis.
usrtk.org/healthwire/i...
usrtk.org/healthwire/i...
Most U.S. infant formulas contain mainly added sugars, posing a serious risk to babies' health, researchers say
Most infant formulas in the U.S. contain mostly added sugars instead of natural lactose, which experts say can harm early development, a new study shows.
usrtk.org
February 25, 2025 at 2:13 PM
“Infants may consume upwards of 60 grams of added sugars per day, or the equivalent of two soft drinks per day if they are entirely formula-fed,” researchers say in the study, published yesterday [Feb. 24, 2025] in the Journal of Food Composition and Analysis.
usrtk.org/healthwire/i...
usrtk.org/healthwire/i...