“Superfood” has been a buzzword for years, but it’s really more of a marketing term than an official food-industry classification. Still, superfoods generally have one thing in common: They pack a significant nutrient punch. They may be high in one nutrient in particular, or they might contain several phytonutrients, antioxidants, other vitamins, and/or minerals. And since these perks come in a small volume of mostly low-calorie food options, they have an even greater appeal in our weight-obsessed culture. Some superfood all-stars of the recent past include blueberries, dark chocolate, oats, pistachios, and dark leafy greens such as kale and spinach.