Philip Longman has a fine piece in Foreign Policy about the graying of the world population. The drastic decline in the number of babies, and the growing proportion of the population that is old, is a story I have written about before.
It is also well known that Americans, and the world population in general, is growing dangerously fat.
Longman offers a new detail that I had not considered before.
The unprecedented rates of obesity means that middle-aged people are more disabled now than they were in the past. This, in turn, means that they will be even more disabled when they are old. Which will come very soon.