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David Ludwig MD, PhD

@davidludwigmd.bsky.social
196 followers 20 following 55 posts

Endocrinologist, Nutrition Researcher, Public Health Advocate. #1 NYT bestselling author of Always Hungry? and cookbook Always Delicious.

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David Ludwig MD, PhD @davidludwigmd.bsky.social · 01/10/2026
At European Assoc for the Study of Diabetes meeting, Milan 👉YES — new drugs have made a big impact on diabetes care 👉NO — drugs will not be the stand-alone solution to chronic disease 👉Disconcertingly — Pharma dominates virtually every aspect of the meeting, from scientific agenda to floor space
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 17/09/2026
A NY Times opinion notes that the food industry has played an insidious role undermining sensible food regulations. But the difficulty defining UPF extends beyond politics to a basic misunderstanding of how food affects health. Letter-to-Editor at bottom of link: www.nytimes.com/2026/09/16/o...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 09/09/2026
On efforts to fund a ketogenic diet + GLP-1 drug trial: "[Ludwig] asked the major manufacturers of GLP-1s for funding, with no success." "If your only tool is a hammer ... [you'll] want to make an argument to keep hammers available for lifelong use” www.washingtonpost.com/health/2026/...
washingtonpost.com
The largely hidden force helping drive America’s craze for weight-loss drugs
Firms are spending hundreds of millions of dollars to convince doctors to prescribe GLP-1 drugs.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 17/07/2026
Defining ultra-processed food for regulatory purposes is proving “quite challenging" at @fda.gov www.fooddive.com/news/ultrapr... Imagine that! www.nejm.org/doi/full/10....
fooddive.com
Defining ultraprocessed foods proves ‘challenging,’ FDA food head says
Donald Prater, acting deputy commissioner of food, said the Trump administration is still making the definition a “priority.”
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 14/07/2026
GLP-1s are great drugs for diabetes but not a cure. In a new "real-world" study: 👉Only 1 in 6 patients on GLP-1s came off insulin 👉GLP-1s were no better than SGLT2i or DPP4i Could a ketogenic diet boost effects of GLP-1s and help more patients come off insulin? www.acpjournals.org/doi/10.7326/...
acpjournals.org
Comparative Effectiveness of Glucagon-like Peptide-1 Receptor Agonists Versus Oral Agents for Insulin Discontinuation in Type 2 Diabetes: A Target Trial Emulation: Annals of Internal Medicine: Vol 0, ...
Background: Addition of glucagon-like peptide-1 receptor agonists (GLP-1RAs) to basal insulin can decrease insulin requirements, but whether it permits insulin discontinuation is unclear. Objective: T...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 07/07/2026
The Futility of Calorie Counting “You could put sawdust into a bomb calorimeter and you would get basically 4 calories per gram.... If you’re a termite, yes, you’ll get calories from it. But humans won’t.” apnews.com/article/calo...
apnews.com
Why losing weight isn't just about counting calories — and what to do about it
When it comes to losing weight, it turns out the simple math of counting calories doesn’t always add up.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 03/07/2026
Among the 10 "Best Healthy Eating Advice" of 2026 👉Be wary of low-carb diets 👉Little support for intermittent fasting 👉Avoid too much protein 👉Eat more fiber 👉Eat oats 👉Eat peas At least for low-carb, it would be great if NYTHealth seeks contrasting expert opinion www.nytimes.com/2026/07/02/w...
nytimes.com
The Best Healthy Eating Advice of 2026 (So Far)
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 01/07/2026
Does a sugary diet make teens sleep poorly? Or does poor sleep make them crave sugar? 👉Perhaps both, according to a new study with my Danish collaborators David Horner, Morten Arendt, and others. Open access to full paper linked in the press release: news.ku.dk/all_news/202...
news.ku.dk
Researchers to teens: get to bed – it’s good for your blood sugar
If you’re 18, getting a bit more sleep could matter more than you think. New research from the University of Copenhagen and COPSAC shows that even in healthy young people, longer nights of sleep are l...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 28/06/2026
Big journal (AJPH, Lancet) articles on Ultra-Processed Foods: "It's like a criminal trial in which the jury only hears from the prosecutors. The judge has excluded the defense attorneys from participating. Of course, the jury will convict" uncertaintyprinciples.substack.com/p/bad-air-or...
uncertaintyprinciples.substack.com
"Bad Air" or the Tobacco Industry Playbook?
Which is the better metaphor for the controversy over ultra-processed foods?
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 25/06/2026
New paper: Have CONTINUOUS GLUCOSE MONITORS been wrongfully discredited? www.sciencedirect.com/science/arti...
sciencedirect.com
Inappropriate analyses make continuous glucose monitoring appear imprecise
Check access to the full text by signing in through your organization.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 24/06/2026
Delighted to celebrate the 81st birthday of Walt Willett (renowned nutrition researcher) with a 60-mile bike ride. Cambridge -> Concord -> Carlisle -> back 👉 Lifelong #metabolic health Lunch was both Mediterranean (for Walt) and low-carb (for me) adherent: Smoked sockeye, pecorino, nuts
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 23/06/2026
Arguably the most consequential debate in nutrition today —Ultra-Processed Food Like the low-fat diet debacle of the late 20th century, are we building another house of cards? Worth finding your way thru the paywall www.theatlantic.com/health/2026/...
theatlantic.com
A Fancy Name for Junk Food
Does the war on “ultra-processed foods” make any sense?
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 15/06/2026
Summary of Ultra-Processed Food Research @NIH jamanetwork.com/journals/jam... $100M spent on: 👉Confounded observational studies 👉Trials that, per 3 reviews, are basically useless Ironically, a "standardized definition for UPF is currently not available" Let's find a better use for nutrition $$$
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 01/05/2026
Are the Trials of ULTRA-PROCESSED FOOD Reliable? “as good a clinical trial as you can get” “the most important study ever done to explain weight gain” “worse than worthless” 👉These quotes by nutrition experts refer to the same study. Who's right? Open access: www.tandfonline.com/doi/full/10....
tandfonline.com
Is the experimental evidence on ultra-processed food and obesity reliable?
Public health experts have issued widespread calls to target ultra-processed foods (UPF) in nutrition policy to prevent obesity and other diet-related chronic diseases. Several short-term crossover...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 11/04/2026
"Delicious, calorie-rich food — whether home-prepared or packaged — isn’t the problem. What matters is how long we stay satisfied (satiety) relative to calories consumed."
medium.com
Tastiness Is Not the Problem
This essay is adapted from my piece in STAT First Opinion.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 09/04/2026
Do tasty foods make us overeat and gain weight? Nonsense, I argue in a new opinion @statnews.com. Pleasure from food isn't the problem. Focusing on it distracts from the real drivers of food craving and addictive eating behaviors. 👉Free with email sign-up: www.statnews.com/2026/04/09/t...
statnews.com
Tastiness is not why people overeat
“We can’t afford another sweeping restructuring of the food supply based on imprecise interventions and uncertain science,” writes David L. Ludwig.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 03/04/2026
Do highly tasty (“hyper-palatable”) foods make us overeat? Must food manufacturers market bland products to protect the public from obesity? My thoughts in a Perspective in PLoS Medicine. 👉Open access at this link: journals.plos.org/plosmedicine...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 06/03/2026
Ultra-Processed Food Debate Lancet ran a 3-part series by proponents of the Nova/UPF system, calling for adoption of this approach in international food policy. 👉In a 250-word letter and appendix, I raise concerns. Other letters and author reply also published www.thelancet.com/journals/lan...
thelancet.com
Ultra-processed foods in research and policy
Articulating a common sentiment among public health experts, a UK parliamentary committee report published in October, 2024, asserts the “food system is broken”,1 contributing to epidemics of diet-rel...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 04/03/2026
www.youtube.com/watch?v=nzTz...
youtube.com
Why Nutrition Science Is Stuck — And How to Fix It | David Ludwig, MD, PhD
YouTube video by Ty Beal
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 03/03/2026
Why do debates on critical questions in nutrition – from the harms of sugar to the cause of obesity – drag on for decades, leaving science at a standstill? I explore this question through the lens of the science philosopher Thomas Kuhn. Free article link 👇 www.cell.com/cell-metabol...
cell.com
Overcoming impasse in nutrition science
Paradigm clash plays a crucial role in science by strengthening existing conceptual models or facilitating adoption of more useful ones. Here, I argue that this salutary process tends to stagnate in t...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 06/01/2026
“Telling people to eat beef ribeye at triple the price of hamburger has an elitist streak.” “Yet a hamburger has similar nutritional value. It’s kind of like Marie Antoinette saying, ‘Let them eat steak.'”
harvardmagazine.com
Is Ultraprocessed Food Really That Bad? | Harvard Magazine
A Harvard professor challenges conventional wisdom.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 21/11/2025
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...
sciencedirect.com
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…
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 14/10/2025
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...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 13/10/2025
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
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 06/10/2025
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
wapo.st
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.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 17/09/2025
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...
youtube.com
This Will Change Your Mind on Ultra-Processed Foods (Harvard MD PhDs Discuss)
YouTube video by Nick Norwitz
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 10/09/2025
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...
youtube.com
The Ultra-Processed Food Debate: Science, Bias, & Truth
YouTube video by Metabolic Mind
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 09/09/2025
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...
nature.com
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...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 04/09/2025
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...
nejm.org
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.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 07/06/2025
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. 😀
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 05/06/2025
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
youtube.com
The Truth About Nutrition Science: Is The Government Getting it Wrong?
YouTube video by Metabolic Mind
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 03/06/2025
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...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 26/05/2025
Avoid carbs to prevent malaria? Preliminary evidence suggests maybe so ... www.nature.com/articles/s42...
nature.com
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 ...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 25/05/2025
“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.
substack.com
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
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 19/05/2025
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...
link.springer.com
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...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 14/05/2025
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...
uncertaintyprinciples.substack.com
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."
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Reposted by David Ludwig MD, PhD
Center for Health Incentives and Behavioral Economics @pennchibe.bsky.social · 12/05/2025
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...
chibe.upenn.edu
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.
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Reposted by David Ludwig MD, PhD
David Ludwig MD, PhD @davidludwigmd.bsky.social · 27/04/2025
Designed to Fail: Why short-term diet trials cannot solve the epidemics of chronic disease. 👉New blog post (no paywall)
davidludwigmd.medium.com
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
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Reposted by David Ludwig MD, PhD
The BMJ @bmj.com · 30/04/2025
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/...
A researcher looking at data
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Reposted by David Ludwig MD, PhD
Prof Jeffrey S Morris @jsm2334.bsky.social · 28/04/2025
In an associated opinion piece in STAT News (www.statnews.com/2025/04/22/n...),
statnews.com
Short-term diet trials are designed to fail
Does ultra-processed food cause obesity? Maybe, but we’ll never know from short-term trials.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 27/04/2025
Designed to Fail: Why short-term diet trials cannot solve the epidemics of chronic disease. 👉New blog post (no paywall)
davidludwigmd.medium.com
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
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 22/04/2025
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...
bmj.com
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...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 03/04/2025
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
journals.physiology.org
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...
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 02/04/2025
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...
nejm.org
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...
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Reposted by David Ludwig MD, PhD
Pamela Ferdinand @pamelawrites.bsky.social · 25/02/2025
“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
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.
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 25/01/2025
Anti-depressant therapy for Danish winter. 👉Hellerup harbor, water temp 2° C
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 10/01/2025
Will a Low-Carb Diet Reduce Racial & Ethnic Health Disparities? No paywall at this link:
medium.com
Will a Low-Carb Diet Reduce Racial & Ethnic Health Disparities?
Coauthored with Nicholas Norwitz, Diana Thomas, and Cara Ebbeling. Image modified from ChatGTP by Mr Andrew Degryse
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 21/12/2024
NOON, Denmark. Circa solstice. View to the South. In case you were wondering, that moderately bright object about 10° above the horizon is ... the sun 😲
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David Ludwig MD, PhD @davidludwigmd.bsky.social · 17/12/2024
New American Diabetes Assoc guidelines for obesity in Type 2 diabetes. Once again: "500–750 kcal/day energy deficit is recommended" (hasn't this been tried for a century???) Regarding diet, "no single way is best" 👉Low-carb diets mentioned exactly ... 0 times diabetesjournals.org/care/article...
diabetesjournals.org
8. Obesity and Weight Management for the Prevention and Treatment of Type 2 Diabetes: Standards of Care in Diabetes–2025
The American Diabetes Association (ADA) “Standards of Care in Diabetes” includes the ADA’s current clinical practice recommendations and is intended to pro
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