Fascinating read. At first I was thinking things like the introduction of high fructose corn syrup, or microwave dinners, but that doesn't completely explain all of those data points.

This is an interesting comment someone left ... it's one of the only ones that could potentially explain all of the results, outside of some outliers like the altitude effect.

> With these premises it seems almost obvious to attribute the obesity pandemic to an external factor – for instance, virus or bacteria. My money is on gut bacteria being altered by some bacteria/virus, of which transmission is relatively hard (but it persists), which spread like wildfire in the last forty years and which thrives on cafeteria diets (which would explain its emergence in the second half of the 20th century).