Scott examines the relationship between altitude and obesity, then explores and ultimately dismisses the theory that increased atmospheric CO2 could be causing the obesity epidemic.
Longer summary
Scott Alexander explores the correlation between altitude and obesity rates in the US, noting that people living at higher elevations tend to be less obese. He discusses various studies on altitude anorexia and hypoxia's effect on weight loss. The post then transitions to a speculative theory about whether increased atmospheric CO2 from global warming could be causing the obesity epidemic. While intriguing, Scott ultimately concludes that this theory is likely not true, based on geographical inconsistencies, submarine studies, and the small magnitude of potential effects.
Shorter summary