Clearing the confusion on saturated fat once and for all | Dr Gil Carvhalo, MD, PhD

Listen Now

In Episode #243, Dr Gil Carvalho joins me to analyse a controversial new study on saturated fat, offering a definitive conclusion on what the science says.

“Without exception, [a paper like this] blows up on social media. It’s highly celebrated because it’s contrary and it sounds like good news.”

As we settle into 2023, there are still loose ends to reflect on and assess from last year. In today’s episode, Gil Carvalho, MD PhD returns to break down a controversial study released in late December. Focusing on saturated fats and having been well circulated online, this study positions saturated fats as a “bogeyman” not to be feared – but how does this claim stack up against the general scientific consensus?

Gil Carvalho, MD PhD is a physician, research scientist, science communicator, speaker, and writer. He has been a member of the Genetics Society of America and the American Society for Neuroscience and has achieved accolades including a Delill Nasser Award for Professional Development in Genetics and a Mathers Foundation award. With a career spanning both medical practice and research, Dr Carvalho offers a rational, practical, and actionable perspective on this topic.

“It’s a sobering view of how things are shared on social media and how we are exposed to information. Oftentimes… the lowest quality information gets pushed in our face the most intensely. We have to be very careful, and scrutinise.”

In Episode #243, we examine the aforementioned study with a researcher’s eye, breaking down analysis techniques in a way that is applicable to most scientific papers. We expand on the topic of saturated fat, reconciling the difference between cardiology guidelines and isolated studies, saturated fat, and bio-individuality. We also cover common misunderstandings, genetics, and the principles of saturated fat consumption.

Specifically, we discuss:

  • Intro (00:00)
  • Saturated fat misunderstandings: Is saturated fat bad? (17:20)
  • Principle 1: Dose matters? — How much saturated fat is too much? (22:07)
  • Is no saturated fat the goal? (30:12)
  • Principle 2: Replacement nutrient matters (31:54)
  • Principle 3: Source matters (45:53)
  • Mechanisms: Saturated fat and heart disease (50:48)
  • Saturated fats and genetics (55:47)
  • Target ApoB level (59:40)
  • Importance of lifetime exposure (1:03:02)
  • Statins and heart disease risk: Are statins bad for you? (1:08:53)
  • Mendelian randomization studies (1:10:52)
  • The totality of evidence (1:15:59)
  • Saturated fats and total mortality (1:17:46)
  • Saturated fat and liver health (1:19:51)
  • Gaps in the research (1:20:43)
  • Common arguments against lowering saturated fat (1:23:52)
  • Outro (1:38:36)

It was great to have Dr Carvalho back on the show to round out what the science says about saturated fat. Dr Carvalho’s communication style balances evidence with accessibility, and I hope you found this episode clarifying and useful.

To explore more of Dr Gil Carvalho’s work, you can find him on YouTube. You can also connect with him on Twitter and Facebook, and listen to our previous conversation in Episode #207.

The best way to support the show is to use the products and services offered by our sponsors. To check them out, and enjoy great savings, visit

Enjoy, friends.


More about Gil Carvalho, MD PhD

Gil Carvalho, MD PhD is a physician, research scientist, science communicator, speaker and writer. Dr. Carvalho trained as a medical doctor in the University of Lisbon, in his native Portugal, and later obtained a PhD in Biology from Caltech (California Institute of Technology). He has published peer-reviewed medical research spanning the fields of genetics, molecular biology, nutrition, behavior, aging and neuroscience.

In parallel with his research career, Dr. Carvalho also has a passion for science communication. In 2018, he launched Nutrition Made Simple, which aims to convey fundamental nutrition concepts to a lay audience via educational videos. His content has been watched by over a quarter million people.

Dr. Carvalho’s research contributions at Caltech, where he trained with pioneer geneticist Seymour Benzer, included the identification of genetic and nutritional mechanisms of longevity.

Dr. Carvalho also pursued research, with neuroscientist Antonio Damasio, on mechanisms of neural signal transmission in the sensory system and the neural basis of interoception and feeling.

He has been a member of the Genetics Society of America and the American Society for Neuroscience. His accolades include a Delill Nasser Award for Professional Development in Genetics and a Mathers Foundation award. Both his research contributions and his expert commentary are regularly featured in the media, including The Proceedings of the National Academy of Sciences, Nature Methods, the San Diego Union-Tribune, Quanta magazine and ScienceDaily. He is also a contributor to the Institute of Limbic Health and the T. Colin Campbell Center for Nutrition Studies.

Supporting studies

  • Adherence to the Healthy Eating Index-2015 and Other Dietary Patterns May Reduce Risk of Cardiovascular Disease, Cardiovascular Mortality, and All-Cause Mortality • PMID: 31529069
  • Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis • PMID: 24723079
  • Chocolate and Prevention of Cardiovascular Disease: A Systematic Review • PMID: 16390538
  • How effective are current dietary guidelines for cardiovascular disease prevention in healthy middle-aged and older men and women? A randomized controlled trial •  PMID: 25787998
  • Manifestations of coronary atherosclerosis in young trauma victims–an autopsy study • PMID: 8335815
  • Reduction in saturated fat intake for cardiovascular disease • PMID: 32428300
  • Saturated fats and cardiovascular health: Current evidence and controversies • PMID: 34649831
  • Saturated Fats and Health: A Reassessment and Proposal for Food-Based Recommendations: JACC State-of-the-Art Review • PMID: 32562735
  • Saturated Fat as Compared With Unsaturated Fats and Sources of Carbohydrates in Relation to Risk of Coronary Heart Disease: A Prospective Cohort Study • PMID: 26429077
  • Saturated fat: villain and bogeyman in the development of cardiovascular disease? • PMID: 36059207
  • The Effect of Coconut Oil Consumption on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Clinical Trials • PMID: 31928080
  • 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk • PMID: 31504418

Additional resources

Search 'The Proof' in your favourite podcast streaming app

If you listen on Apple Podcasts be sure to hit ‘subscribe’ or ‘follow’ on Spotify so you are instantly notified when I release new episodes each week.

the proof is in the plants

Haven't purchased
The Proof is in the Plants?

Some other episodes you might like

Search The Proof