OK at first glance you might think - well it beat Atkins, beat the zone, beat paleo - but then you'll look above & see weight watchers (umm, really ..even with their almost 100% failure rate over 12 month time frame?), slimfast (MY GOD WHAT!!!!!!!! I'm left speechless!). Strangely enough the Government devised diet (called DASH) won. There criteria seems to be stuff like social support & ease so vegan wouldn't be top as is can be hard some places (hence we learn to go prepared-it's called planning!)
Oh well make up your own mind check out the top rated diets
Here's the categories, note vegan got joint 2nd in diabetes control