Why can't anyone agree on a healthy diet?: The Story

The egg

In 1980, the United States government published its first Dietary Guidelines for Americans. The document told 226 million people to cut fat, eat more grains, and switch to margarine. Americans dutifully shifted — fat consumption dropped, grains rose, margarine replaced butter. Obesity tripled. Type 2 diabetes quadrupled. Heart disease remained the leading cause of death every single year of the experiment.

In 2015, the same government quietly reversed itself on cholesterol. Eggs — vilified since 1968 when the American Heart Association said no more than three per week — were fine again. Forty-seven years of egg anxiety. No apology. Just a sentence in an appendix. The reversal would be comic if the body count were lower. Roughly 700,000 Americans die of heart disease each year. Metabolic syndrome now affects 40 percent of adults.

The supermarket

Imagine explaining this to a time traveler. The supermarket is a Le Guin novel: an alien food distribution center where every aisle contradicts the previous one. Aisle three says whole grains are the foundation of health. Aisle four sells bone broth because a growing movement argues grains are inflammatory. Aisle seven offers low-fat yogurt sweetened past diabetic thresholds. Aisle nine promises to undo the damage from aisles three through eight. The checkout magazine rack features the Mediterranean diet next to a story about why the Mediterranean diet study was never properly controlled.

Four groups of credentialed, passionate people stand in this supermarket and see entirely different buildings. Every RCT since 1980 has been read, and the evidence-based camp can explain why most prove less than they claim. Physicians who reversed their own metabolic syndrome by eating like their great-grandparents built the ancestral health case from blood work, not ideology. Then there are people who stopped counting macros and discovered the anxiety about food was causing more damage than any food — the intuitive camp has the cortisol data. And underneath every aisle, a subsidy structure: corn and soy are in everything not because they are healthy but because the government pays farmers to grow them, a fact the industrial critics consider more explanatory than any nutrient study.

The settled part

The dietary advice that governed two generations was, at minimum, incomplete. Whether the fix is better science, older food, less obsession, or different farm policy is the question none of these camps can answer for the others. The species that sequenced its genome cannot agree on breakfast. The disagreement would be funny if 40 percent of the country were not metabolically ill.

The species that landed a rover on Mars cannot agree on whether eggs are good for you. In 1980, the US government told the country to cut fat and eat grains. Obesity tripled. Diabetes quadrupled. In 2015, the same government reversed itself on cholesterol with a sentence in an appendix and no apology. The supermarket is an alien food distribution center where every aisle contradicts the previous one, and the cheapest calories are the cheapest because the government pays farmers thirty billion dollars a year to grow corn and soybeans while subsidizing zero broccoli. A head of broccoli costs $2.50. A two-liter bottle of Coca-Cola costs $1.89. The price difference is not an accident. It is a subsidy structure expressing itself as a shopping cart. Meanwhile, four camps of credentialed people cannot agree whether the fix is better trials, older food, less anxiety, or different farm policy. Forty percent of American adults are metabolically ill. The disagreement would be funnier if the body count were lower.

Perspectives:
- Evidence-based medicine
- Ancestral health
- Intuitive health
- Industrial critics