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How Different Diets Impact Your Health | Dr. Christopher Gardner

Episode 228 May 12, 2025 2h 51m 18 insights
My guest is Dr. Christopher Gardner, Ph.D., professor of medicine and director of nutrition studies at Stanford. He is known for his pioneering research on the impact of dietary interventions on weight loss and health. We compare ketogenic, vegetarian, vegan and omnivorous diets—and why there is no one-size-fits-all approach. All agree, however, that eliminating or dramatically reducing processed foods is best for health. We discuss the protein needs controversy; plant vs. animal proteins; the importance of fiber and low-sugar fermented foods for gut health and inflammation; and how diet affects gene expression. We also review food allergies—including gluten, wheat, dairy and soy—as well as raw dairy. The episode offers data-supported advice for healthier eating. Read the episode show notes at hubermanlab.com.
Actionable Insights

1. Consume Fermented Foods Daily

Incorporate fermented foods like plain yogurt, kefir, kombucha, kimchi, and sauerkraut into your daily diet to significantly increase gut microbial diversity and reduce inflammatory markers in your body.

2. Fiber Intake: Assess Gut Diversity First

If your baseline gut microbial diversity is low, prioritize increasing fermented food intake before drastically increasing fiber, as a ‘fire hose of fiber’ might lead to adverse inflammatory responses.

3. Aim For Three Fermented Food Servings

Strive to consume at least three servings of low-sugar fermented foods daily, as study participants maintained this intake and experienced sustained benefits even after the formal study period.

4. Adopt The “Protein Flip” Meal Structure

Implement the ‘protein flip’ by making vegetables, grains, and beans the main focus of your plate, with meat serving as a smaller accompaniment (e.g., two ounces) rather than the central component.

5. Eat Less, Better Quality Meat

Aim for ’less meat, better meat’ by reducing overall consumption and choosing high-quality, sustainably sourced options, which can offer health benefits and potentially balance your food budget.

6. Avoid Standard American Diet

Avoid the standard American diet, which is problematic because it’s full of processed, packaged food that is convenient, inexpensive, and addictively tasty but unhealthy.

7. Prioritize Whole Foods, Shun Packaged

Recognize that different people thrive on different diets, but universally avoid packaged processed food for better health outcomes.

8. Avoid Foods With Cosmetic Additives

Minimize consumption of foods containing cosmetic additives (dyes, flavorants, gelling agents), as these ingredients are primarily used to enhance appeal rather than provide nutritional value, signaling ultra-processed food.

9. Re-engage With Food Preparation

Actively engage in preparing your own food and advocate for systems that make the acquisition and preparation of high-quality, nutritious food more accessible and affordable for everyone.

10. Embrace Dietary Resilience & Experimentation

Experiment with different diets to find what works for you, as humans are incredibly resilient and can thrive on various dietary approaches.

11. Healthy Low-Carb Or Low-Fat Both Work

Choose either a healthy low-carb or a healthy low-fat diet for weight loss, as both approaches can be equally effective when implemented with high-quality, whole foods.

12. Plant Proteins Are Complete

Dismiss the myth that plant foods are ‘incomplete’ or ‘missing’ amino acids; all plants contain all 20 amino acids, and strict complementing of beans and grains is generally unnecessary if overall protein intake is sufficient.

13. Redefine Protein Quality Holistically

When assessing protein quality, broaden your perspective beyond just amino acid composition and digestibility to include environmental impact and the presence or absence of other beneficial nutrients.

14. Diversify Grains, Reduce Refined Wheat

Consider reducing the intake of refined wheat, particularly the predominant type found in the U.S. diet, and explore heritage versions of different wheat grains and other diverse grain sources.

15. Evaluate Diets Fairly (Equipoise)

When comparing different diets, ensure each is implemented in its healthiest, most optimal form (e.g., healthy low-carb vs. healthy low-fat) to get a fair assessment of their true effects.

16. Excess Protein Not Stored

Understand that your body does not store excess protein for future use; any protein consumed beyond immediate needs is converted to other forms or eliminated.

17. Raw Milk Doesn’t Cure Lactose Intolerance

Do not rely on raw milk to cure lactose intolerance, as a study showed it provided no relief from symptoms compared to conventional milk.

18. Aspire To Healthful, Sustainable, Tasty Diet

Consciously choose foods that are healthful, environmentally sound, and tasty, aiming for a balanced approach that satisfies all three criteria.