We live in an age of radical diets: Paleo, vegan, low-glycemic, low-carb, Mediterranean, low-fat, high fat (keto). Which one’s best for maintaining a healthy weight? In a 2014 paper, Yale medical researchers surveyed the scientific evidence and came up with a simplifying answer: Diets consisting mainly of “minimally processed foods” point to good health outcomes, whether or not they contain foods people like to debate about, like meat or grains.