Interlude: A Chemical Hunger

A Chemical Hunger, an interesting series on the author's unique theory of obesity, ended in November. It began in July with a dramatic restatement of the mystery of obesity:

The study of obesity is the study of mysteries.

The first mystery is the obesity epidemic itself. It’s hard for a modern person to appreciate just how thin we all were for most of human history. A century ago, the average man in the US weighed around 155 lbs. Today, he weighs about 195 lbs. About 1% of the population was obese back then. Now it’s about 36%.

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Another thing that many people are not aware of is just how abrupt this change was. Between 1890 and 1976, people got a little heavier. The average BMI went from about 23 to about 26. This corresponds with rates of obesity going from about 3% to about 10%. The rate of obesity in most developed countries was steady at around 10% until 1980, when it suddenly began to rise.

Today the rate of obesity in Italy, France, and Sweden is around 20%. In 1975, there was no country in the world that had an obesity rate higher than 15%.

This wasn’t a steady, gentle trend as food got better, or diets got worse. People had access to plenty of delicious, high-calorie foods back in 1965. Doritos were invented in 1966, Twinkies in 1930, Oreos in 1912, and Coca-Cola all the way back in 1886. So what changed in 1980?

Common wisdom today tells us that we get heavier as we get older. But historically, this wasn’t true. In the past, most people got slightly leaner as they got older.

And that's just the start of the mystery episode.

Spoilers: Later, the author (or authors; the about page is quite vague) decide pollution must be the answer. Even later, the suspect pollutant is revealed to be lithium.