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Summary
On episode 331 of 40+ Fitness, Coach Allan sits down with Dr. David Friedman, a number one national bestselling author, doctor of naturopathy, and syndicated TV and radio health expert, and author of Food Sanity.
David built the book’s DIG method after 18 years of watching guests on his own show contradict each other on nutrition: Discovery (the science), Instincts (what your gut tells you), and God (your biology, teeth, and enzymes). He argues that studies alone can’t settle food questions because funding bias skews results, so all three legs of the DIG stool need to agree before you trust a claim.
The conversation uses the method to debunk a string of popular myths: what our ancestors actually ate (closer to a mostly plant-based chimpanzee diet than a meat-hunting caveman), the link between red meat and inflammation, and the widely repeated fear that fish is loaded with dangerous mercury.
Links
- https://foodsanity.com
- https://drdavidfriedman.com
Key Takeaways
- The DIG method evaluates food claims from three angles at once. Discovery is the science, Instincts is your gut sense, and God is your body’s actual biology (teeth, enzymes, digestive system); David says a claim only holds up if all three agree, like a tricycle that needs all its wheels.
- Studies can be bought, so treat single studies with caution. David points out that industry funded research tends to find what the funder wants found, and unfavorable results often simply don’t get published.
- Animal studies don’t automatically translate to humans. Cats are carnivores and rabbits are vegan by nature, so a study on either tells you little about what’s optimal for a human body.
- Cavemen were mostly plant eaters, not meat hunting predators. Forensic evidence points to a primarily plant-based diet, short stocky bodies rather than lean hunters, and meat that spoiled within about five hours of a kill, making it impractical as a daily staple.
- The “no grains until 10,000 years ago” claim doesn’t hold up either. Fossilized grain remnants have been found in caveman teeth, and University of Utah research puts roughly 40 percent of the ancient diet as gluten containing grains.
- David recommends eating like your great-grandparents, not like a caveman. Earlier generations avoided processed food, added hormones, and chemical coloring, and were dramatically less likely to be overweight (3 to 5 percent then versus about 70 percent today).
- Red meat is linked to inflammation through a sugar molecule called Neu5Gc. It’s found in cows but not humans, and the resulting immune response has been tied to colon cancer and heart disease; the World Cancer Research Fund concluded nearly half of colon cancer cases could be prevented by eating less red meat.
- The fish and mercury scare is largely a myth. Of 18 commonly eaten fish, all but mako shark contain more selenium than mercury, and selenium neutralizes mercury’s effect on the brain; cultures that eat fish daily show no mercury toxicity and healthier outcomes, including in pregnancy.
- Fruit sugar isn’t the villain when fiber is present. High fiber, low glycemic index fruits like apples and blueberries buffer their natural sugar and are linked to lower diabetes risk, while artificial sweeteners actually increase hunger and obesity risk rather than helping with weight loss.
“I don’t care what the caveman ate because I just had to find out. Everyone’s always saying eat like a caveman. I care what our great-grandparents ate because that’s our direct line.”
Dr. David Friedman
