Developing countries are really gonna be hit bad owing to lack of health infrastructure and widespread misconceptions over fatness.  Yep, there are some villages in the Southeast Pacific that are going to be wiped out within a generation because they gorge themselves on Western junk food, lack any health education whatsoever, and lack any basic modern healthcare that keep fats alive. The result is populations that are 90%+ obese with children being orphaned en masse because the adults are dropping dead of type two diabetes and heart failure.