What evolution reveals about eating, dieting and fat

August 17, 2026

AI Summary

5 min read

What evolution reveals about eating, dieting and fat

Daniel Lieberman, a Harvard paleoanthropologist and author of Fed Up, has spent years studying how evolution shaped our digestive systems, our appetites, and our bodies' stubborn resistance to losing weight. As part of his research for the book, he and his wife subjected themselves to two-week trials of several popular diets—Atkins, paleo, meal replacement, raw food—to experience firsthand what each demanded and how their bodies and minds responded. The raw food diet was the worst: Lieberman lasted four days, his wife three. The meal replacement diet became "a form of torture" because he missed actual food. The Atkins diet left him craving plants. The paleo diet frustrated him because it banned legumes and grains he considers healthy.

But his deeper argument is not about which diet is best. It is about why we struggle so much with any diet at all, and why the search for a single simple answer is itself part of the problem.

Why evolution makes dieting so hard

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What you'll learn

1 (01:55) **Lieberman’s Self-Experiment: The Worst Diets** - Lieberman describes trying several popular diets for two weeks each, and which ones he found most torturous.
2 (05:10) **Debunking the "Paleo" Premise** - Lieberman explains why the evolutionary logic behind the paleo diet is scientifically flawed.
3 (07:09) **The Atkins Diet: Good Science, Hard Reality** - Lieberman evaluates the high-fat, low-carb Atkins diet, acknowledging its theoretical benefits but questioning its real-world practicality.
4 (09:43) **What Successful Weight Losers Actually Do** - Lieberman cites the National Weight Loss Registry to show that long-term success doesn't come from fad diets.
5 (10:50) **The "Best of All Worlds" Diet** - Lieberman argues for combining the best elements of competing diets rather than choosing one.
6 (13:55) **The Egg Debate: A Case Study in Complexity** - Lieberman uses eggs to illustrate why nutrition advice is often contradictory and oversimplified.
7 (15:10) **Why the "Blue Zone" Diet is Mostly Marketing** - Lieberman critiques the Blue Zone diet, arguing its claims are statistically and methodologically unsound.

+ Full timestamped outline available in the app

Show Notes

When you’re dieting to lose weight, human evolution is often working against you. We’ll talk about why with Daniel Lieberman, author of Fed Up and founder of Harvard’s Department of Evolutionary Biology. He spoke with Terry Gross about diets he’s tested, and the often contradictory information about what’s healthy to eat and what’s not.

Also, book critic Maureen Corrigan reviews Etna, a novel that looks at war through the narration of a dog.

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