Chris Williamson · 2026-08-15 · Chris Williamson (host), Daniel Lieberman
Harvard Professor: “I Tried Every Diet. This Is By Far The Worst.” - Daniel Lieberman
71 research-tied claims examined: 6 contradicted 7 overstated 5 context 43 supported 10 unverified
10 No source found (not proven false)
Humans can survive without consuming dietary carbohydrates and most fats, but cannot survive without dietary essential amino acids and two essential fatty acids (omega-3 and omega-6).
"You can live without eating fat and you can live without eating carbohydrates, but you cannot live without eating protein... Your body can turn anything into fat and your body can turn your body can transform fats and proteins into sugars. But you cannot There are a bunch of amino acids that are essential. You have to have them in their diet or you'll die. There's actually two fatty acids that you need to eat a little bit of, omega-3 and omega-6, but apart from that, you you do need to eat protein." (said at 0:14:43)
No published record directly matching the exact multi-part claim was retrieved. While classic human nutritional biochemistry recognizes nine indispensable (essential) amino acids and two essential fatty acids (linoleic acid and alpha-linolenic acid) as dietary requirements, alongside endogenous glucose production via gluconeogenesis, no fetched publication directly evaluated this specific assertion; this does not prove the claim false.
Singer James Blunt developed scurvy after adopting an all-meat diet.
"In the book, I recount, you know, James Blunt, the English singer... went on an all-meat diet and ended up getting scurvy." (said at 0:12:05)
No published record matching the claim that singer James Blunt developed scurvy after adopting an all-meat diet was located; this does not prove the claim false.
Demographer Saul Newman published a study finding that only 18% of reported centenarians in Blue Zones had birth certificates.
"He did a deep dive into these Blue Zones and found out that only 18% of the people in these Blue Zones actually had birth certificates." (said at 0:37:03)
No published record matching Saul Newman's study finding that only 18% of reported centenarians in Blue Zones had birth certificates was located; this does not prove the claim false. While critical discussions of Blue Zones and age validation errors exist in the longevity literature (such as critiques of birth registration accuracy and clerical errors in extreme age records), a published peer-reviewed study verifying the specific figure of 18% having birth certificates by demographer Saul Newman could not be retrieved in indexed databases.
The average adult human circulating bloodstream contains approximately one and a half teaspoons of glucose.
"In fact, I think the average human being has about a teaspoon and a half of glucose in their entire bloodstream." (said at 0:45:15)
No published record matching the claim that the average adult human circulating bloodstream contains approximately one and a half teaspoons of glucose was located; this does not prove the claim false.
Human population grew from a few million people prior to the invention of agriculture (around 600 generations ago) to approximately 1 billion people by the end of the agrarian era.
"The population of the world by the end of the farming era was up to about a billion people from probably just a few million from before farming was invented, which is only what, about 600 generations ago. So in 590 generations, the world got up from about a few million to a billion people." (said at 1:22:00)
No published record matching the claim that human population grew from a few million prior to agriculture (~600 generations ago) to approximately 1 billion by the end of the agrarian era was located; this does not prove the claim false.
Industrial roller milling technology to separate the germ and bran from whole grain flour was developed in Hungary in the late 19th century.
"And it wasn't until the late 19th century—actually it was in Hungary, in the Industrial Revolution—that we figured out how to mill flour to get rid of the germ and the endosperm." (said at 1:24:40)
No published record matching the claim that industrial roller milling technology to separate grain components was developed in Hungary in the late 19th century was located; this does not prove the claim false.
Doritos contain approximately 30 ingredients.
"Doritos: go get a package of Doritos—don't necessarily eat them—but there are 30 ingredients in Doritos the last time I counted" (said at 1:35:40)
No published scientific record matching the claim regarding the exact ingredient count of Doritos packaging was located; this does not prove the claim false.
Approximately 40% of American adults are classified as obese, and an additional 35% are classified as overweight.
"40% of American adults are classified as having obesity and another 35% are classified as being overweight. So only one in four Americans today— is actually, by BMI classification, which has its own problems, considered normal weight." (said at 1:37:17)
No published record matching the claim that approximately 40% of American adults are classified as obese and an additional 35% as overweight by BMI classification was located; this does not prove the claim false.
Blending a banana allows the human digestive tract to extract more energy from it than consuming the banana whole.
"If you take a banana and you blend a banana, you get more energy from that banana than if you just eat the banana whole. People have done that experiment." (said at 1:40:56)
No published record matching the specific claim that blending a banana allows the human digestive tract to extract more net energy from it compared to eating it whole was located; this does not prove the claim false.
McDonald's French fries in the United States contain 18 ingredients, compared to three ingredients in the United Kingdom (one being optional salt).
"I think French fries from McDonald's in the US have got 18 ingredients, and in the UK they've got three and one of them's salt and that one's optional." (said at 2:06:05)
No published record matching the claim regarding the exact number of ingredients in McDonald's French fries in the United States compared to the United Kingdom was located; this does not prove the claim false.
Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.