The trend has been driven mostly by large increases in poultry, pork and farmed fish, while beef has declined slightly. I suspect the doubling of pork consumption is mostly driven by Asia, because pork is the meat of choice in much of Asia, and pork intake hasn't changed much in affluent nations. As incomes have increased in much of Asia, and food system industrialization has driven down meat prices, per capita meat consumption has increased greatly, displacing grain/legume/tuber consumption as in many other parts of the world. This trend has not yet run its course-- per capita meat consumption is still increasing in Asia.
I'm not trying to make any grand points about the meaning of these trends for human health. Just posting the graph because I think it's interesting to understand diet trends over time.
These data come from the Food and Agriculture Organization, via the Earth Policy Institute data center.
* These data don't include wild fish.
** I don't like the term "developing countries" very much because it strikes me as condescending, but I don't know what else to use.