3: Flexitarian diet

The flexitarian diet, developed by the registered dietitian Dawn Jackson Blatner, rose through the rankings in 2018 to the #3 spot. It's geared toward those who are interested in being vegetarian but don't want to give up meat entirely. It asks dieters to add "new meat" to their diets, like protein-packed tofu, beans, lentils, nuts, and eggs. But if you crave meat once in a while, it's not a big deal.

The diet ranked as the second easiest to follow.

[Photo via @sweetgreen]

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