So does freezing. You can freeze them for two weeks, then defrost and eat raw.
But surely you want the nutrient value from the plant foods? If you are eating, lets say kale, the calorie value is low anyway. Raw kale is hard to digest, full of oxalic acid which prevents mineral absorption and let's face it is downright nasty. But cooked kale, maybe in a soup, is both more palatable and more nutrient dense.