This leafy green tops the chart as one of the healthiest vegetables, thanks to its impressive nutrient profile. One cup (30 grams) of raw spinach provides 56% of your daily vitamin A needs plus your entire daily vitamin K requirement — all for just 7 calories (1).

By those standards, seedy outgrowths such as apples, squash and, yes, tomatoes are all fruits, while roots such as beets, potatoes and turnips, leaves such as spinach, kale and lettuce, and stems such as celery and broccoli are all vegetables.