Home Andrew Huberman Episode
Andrew Huberman · 2025-05-12

How Different Diets Impact Your Health | Dr. Christopher Gardner

Stanford nutrition scientist Christopher Gardner debunks protein, plant-protein, and processed-food myths while championing a whole-food, plant-forward 'protein flip' diet.

How Different Diets Impact Your Health | Dr. Christopher Gardner
The guest

Dr. Christopher Gardner: Professor of medicine and director of nutrition studies at Stanford. He runs rigorous, calorie- and macronutrient-matched dietary trials (published in JAMA and NEJM) and served on the U.S. Dietary Guidelines Advisory Committee.

What this episode covers

Huberman and Gardner work through the biggest controversies in nutrition science: how much protein people actually need, whether plant proteins are inferior to animal proteins, and what the science says about ultra-processed foods, dyes, and additives. Gardner explains why the RDA for protein is already a generous, buffered number, why the body cannot store excess protein, and why plants contain all amino acids (just in different proportions). They explore the politics and funding of nutrition research, industry vs. investigator bias, and Gardner's famous diet studies (A-to-Z, DIETFITS, keto vs. Mediterranean, Beyond Meat vs. red meat, and the Netflix twin study). The conversation lands on practical optimism: fixing the food supply, getting chefs into schools and institutions, and the anti-inflammatory power of low-sugar fermented foods.

Also referenced (named, not recommended)

BookReferenced

The Omnivore's Dilemma

Michael Pollan

“Michael Pollen has a great quote on this, the author of Omnivore's Dilemma.”— Christopher Gardner
BookReferencedISBN verified

Every Twelve Seconds

Timothy Pachirat

“for his doctoral thesis went and worked in a slaughter house for a year undercover and published a whole book on this. And the title of the book is every 12 seconds.”— Christopher Gardner
ProductReferenced

Beyond Meat

Beyond Meat

“I pitted uh Beyond Meat versus Red Meat for cardioabolic outcomes and the Beyond Meat won in several categories over the red meat.”— Christopher Gardner
ProductReferenced

Impossible Meat (Impossible Burger)

Impossible Foods

“You put up the list of ingredients for Beyond Meat or Impossible Meat and then you compare it to the ingredients in beef.”— Andrew Huberman
ProductReferenced

Nutella

Ferrero

“here's the Nutella you sell here and here's the Nutella I buy there. I've had multiple people bring those up to me and show me the different ingredients.”— Christopher Gardner
MediaReferenced

You Are What You Eat: A Twin Experiment

Louie Psihoyos

“you're number three on Netflix. Uh 50 million people watched the docue series in January alone.”— Christopher Gardner
MediaReferenced

The Game Changers

Louie Psihoyos

“He also did Game Changers, which was elite athletes on plant-based diets.”— Christopher Gardner
MediaReferenced

The Cove

Louie Psihoyos

“He got an Academy Award a decade ago for The Cove, which was a documentary about dolphin slaughter in Japan.”— Christopher Gardner

Big reveals from this episode

  • Gardner's tiny 16-person study found raw milk did NOT cure lactose intolerance, contradicting the producer's marketing claims that persist on his website.
  • Gardner discloses he has taken funding from avocado, soy, and Beyond Meat industries, and Beyond Meat beat red meat on cardiometabolic markers in his study.
  • He argues there is no storage depot for excess protein, so high-protein eaters simply burn it as energy or convert it to carbs.
  • The protein RDA is set two standard deviations ABOVE the nitrogen-balance requirement, so 97.5% of people already exceed their needs.
  • Gardner busts the 'incomplete plant protein' myth, showing all plants contain all 20 amino acids in proportions strikingly similar to meat.
  • In the twin study, the vegan twins were biologically younger by epigenetic clocks and had longer telomeres after just eight weeks.
  • The Stanford fermented-foods study found 20 inflammatory markers dropped and microbial diversity rose with six servings/day of fermented food.
  • Fiber's benefit was personalized, not universal: people with low baseline gut diversity had an inflammatory reaction to a sudden 'fire hose of fiber.'

Worth remembering

  • About 90% of the grains Americans eat is wheat, which Gardner links to widespread gluten sensitivity.
  • The NOVA ultra-processed classification lists 150 'cosmetic additive' molecules, but it even flags turmeric and pectin.
  • Banning all ultra-processed additives would wipe out roughly 60% of grocery store items, including some whole-wheat breads and yogurts.
  • The Culinary Institute of America promotes the 'protein flip': plants/grains/beans at the center of the plate with meat as a 2-ounce condiment.
  • Protein RDAs trace back to 1960s nitrogen-balance studies on Vietnam-era conscientious objectors kept in 'penthouse' suits at Berkeley.
  • Humans absorb roughly 80-90% of protein from food, even plant protein bound in fiber.
  • Gardner's Netflix twin documentary hit #3 and was watched by about 50 million people in January alone.
  • Six servings of fermented food per day is only about 300 calories; one bottle of kombucha counts as two servings.
  • Some microbes that bloomed in the fermented-food group weren't even present in the foods eaten, suggesting they expanded once the gut environment changed.
  • Microbiome benefits may require 'residence' of a microbe; otherwise you may need to keep eating the yogurt daily for the effect to persist.