Those converted feed directly on electricity, through a power socket attached to their sternums. Their cybernetic implants have transformed mankind - everyone is beautiful, everyone is healthy, everyone is thin. The stem regulates everything.
Meanwhile, the Pukes are left to scavenge in the gutter, their minds lost to starvation. Forced to squabble over what few crumbs remain, they've resigned themselves to living like the walking dead, shambling through a world of the eternally young...
Until the day it all comes crashing down.