top of page

You Are What You Eat, Netflix and the Twins Study. Peter Attia and Christopher Gardner in Conflict.

Updated: Jun 1

Attia Gardner Twins Netflix

The online health ecosystem is often filled with argument and conflict, especially when it comes to the complexities of nutritional science. A recent study that formed the basis of a Netflix health documentary, You Are What you Eat: A Twin Experiment, has highlighted differences between two health professionals whose work and musings we enjoy: Dr. Peter Attia and Professor Christopher Gardner.

Is this a storm in a teacup or is there something more important involved? We believe the latter.


In this article we will not critique the documentary itself, we will focus on the results of the trial that it followed. The published study, entitled Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins, A Randomized Clinical Trial (see link to study at bottom of page) tried to answer the following question:

  • "Question  What are the cardiometabolic effects of a healthy plant-based (vegan) vs a healthy omnivorous diet among identical twins during an 8-week intervention?

  • Findings  In this randomized clinical trial of 22 healthy, adult, identical twin pairs, those consuming a healthy vegan diet showed significantly improved low-density lipoprotein cholesterol concentration, fasting insulin level, and weight loss compared with twins consuming a healthy omnivorous diet.

  • Meaning  The findings from this trial suggest that a healthy plant-based diet offers a significant protective cardiometabolic advantage compared with a healthy omnivorous diet."

Prof. Gardner is the author of the study. Dr. Attia, with his own expertise in cardiometabolic health, delivered a strongly worded critique.


If you have yet to see the documentary series, it is available on Netflix. The trailer (available here) does not require an account to view...

Why Does This Matter?

Dr. Attia is a very popular and acclaimed longevity expert, with a large online following. Author of the bestselling book "Outlive" he wields great influence in the public's understanding of health.

Prof. Gardner, a research scientist at Stanford, is less well known. In general, scientists (stuck in their research) tend to be much lower profile, and less heard, than their contemporaries in health. Unlike Attia, Gardner (while now featured in a documentary) does not have his own YouTube channel, podcast nor a published and well promoted book.

When Dr. Attia makes disparaging and public comments on Dr. Gardner's work, it is important not just to hear the criticism but also to hear the response.

Dr. Peter Attia's Criticism

Attia criticises both the documentary and the scientific trial itself, essentially stating that the study lacks any real rigour to answer the question.

"Failing Science 101. Though the issue of diet satisfaction limits our ability to interpret the long-term implications of these results, it still is not the most critical shortcoming of this study. By far, that distinction belongs to the investigators’ categorical failure to isolate and test a specific independent variable – which, as emphasized in any sixth-grade science class, is perhaps the most basic requirement for hypothesis testing."

"I could go on for days about other shortcomings of this study... the basic study design and the entire premise upon which it is based are so deeply flawed."

These are strong words against a well published and well respected scientist. Click on image below to read Attia's commentary in full.


Prof. Cristopher Gardner's Response

Prof. Gardner has recently been provided a platform to hear the criticism and to provide a response.

The essence of his response is that the study methods are controlled, as best as can be done in a real world setting. This provides results that are relevant to real world outcomes, how people actually live and eat, that this is a strength of the study.

Click on image below to see the video (15 mins).


Where Do You Stand?

Nutritional science is complicated and often confusing. Research in test tubes or randomised control trials can be stymied when confronted by the real world scenarios... life itself.

Attia often appears to take a black and white approach, and it serves him and his individual patients well. Gardner has a different perspective, looking to a broader vision of how nutritional science and health can be put into practice.

Having seen both arguments, what do you think, where do you stand?

Are Attia's comments justified? Are Gardner's responses valid?

When it comes to health you have to do something that you enjoy and can stick with. Short-term fixes provide short-term results. Consistency is a key driver of success and 'turning up' every day counts.

Stay Healthy,


health book recommendations Singapore

Achieve Your Dietary and Health Goals

Your health, physical – mental – social - is complex and affected by multiple factors within and outside of your control. Our consults and programmes address the whole person, the root causes of ill health and maximising your health, performance & vitality.

Contact us to arrange an introductory call, to learn how we can support your and your team's journey to health. We are based in Singapore and work with clients globally.

Take the first step. Book a Whole Health Consult to assess, identify and prioritise key factors (known and unknown) that affect your health. And receive personalised recommendations on how to address them.

Want to put recommendations into action? Learn more about our programmes for individuals or teams.


Related Resources and Studies

The studies referenced:

Landry MJ, Ward CP, Cunanan KM, Durand LR, Perelman D, Robinson JL, Hennings T, Koh L, Dant C, Zeitlin A, Ebel ER, Sonnenburg ED, Sonnenburg JL, Gardner CD. Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins: A Randomized Clinical Trial. JAMA Netw Open. 2023 Nov 1;6(11):e2344457. doi: 10.1001/jamanetworkopen.2023.44457. Erratum in: JAMA Netw Open. 2023 Dec 1;6(12):e2350422. PMID: 38032644; PMCID: PMC10690456.

Gardner CD, Landry MJ, Perelman D, Petlura C, Durand LR, Aronica L, Crimarco A, Cunanan KM, Chang A, Dant CC, Robinson JL, Kim SH. Effect of a ketogenic diet versus Mediterranean diet on glycated hemoglobin in individuals with prediabetes and type 2 diabetes mellitus: The interventional Keto-Med randomized crossover trial. Am J Clin Nutr. 2022 Sep 2;116(3):640-652. doi: 10.1093/ajcn/nqac154. Erratum in: Am J Clin Nutr. 2022 Dec 19;116(6):1904. PMID: 35641199; PMCID: PMC9437985.


Fadnes LT, Celis-Morales C, Økland JM, Parra-Soto S, Livingstone KM, Ho FK, Pell JP, Balakrishna R, Javadi Arjmand E, Johansson KA, Haaland ØA, Mathers JC. Life expectancy can increase by up to 10 years following sustained shifts towards healthier diets in the United Kingdom. Nat Food. 2023 Nov;4(11):961-965. doi: 10.1038/s43016-023-00868-w. Epub 2023 Nov 20. PMID: 37985698; PMCID: PMC10661734.

Dybvik JS, Svendsen M, Aune D. Vegetarian and vegan diets and the risk of cardiovascular disease, ischemic heart disease and stroke: a systematic review and meta-analysis of prospective cohort studies. Eur J Nutr. 2023 Feb;62(1):51-69. doi: 10.1007/s00394-022-02942-8. Epub 2022 Aug 27. PMID: 36030329; PMCID: PMC9899747.

Termannsen AD, Clemmensen KKB, Thomsen JM, Nørgaard O, Díaz LJ, Torekov SS, Quist JS, Faerch K. Effects of vegan diets on cardiometabolic health: A systematic review and meta-analysis of randomized controlled trials. Obes Rev. 2022 Sep;23(9):e13462. doi: 10.1111/obr.13462. Epub 2022 Jun 7. PMID: 35672940; PMCID: PMC9540559.

English LK, Ard JD, Bailey RL, Bates M, Bazzano LA, Boushey CJ, Brown C, Butera G, Callahan EH, de Jesus J, Mattes RD, Mayer-Davis EJ, Novotny R, Obbagy JE, Rahavi EB, Sabate J, Snetselaar LG, Stoody EE, Van Horn LV, Venkatramanan S, Heymsfield SB. Evaluation of Dietary Patterns and All-Cause Mortality: A Systematic Review. JAMA Netw Open. 2021 Aug 2;4(8):e2122277. doi: 10.1001/jamanetworkopen.2021.22277. PMID: 34463743; PMCID: PMC8408672.

Bakaloudi DR, Halloran A, Rippin HL, Oikonomidou AC, Dardavesis TI, Williams J, Wickramasinghe K, Breda J, Chourdakis M. Intake and adequacy of the vegan diet. A systematic review of the evidence. Clin Nutr. 2021 May;40(5):3503-3521. doi: 10.1016/j.clnu.2020.11.035. Epub 2020 Dec 7. PMID: 33341313.


bottom of page