Kale
Kale is light in calories — one cup of raw kale only has about 33 calories — but it contains close to three grams of protein and 2.5 grams of fiber per serving.
It’s one of the relatively few foods that contains an omega-three fatty acid, a nutrient that most people rely on fish to get. Like other kinds of lettuce, kale is also high in vitamins and folate.
Blueberries
Blueberries’ claim to fame is their antioxidant content. The fruit has more antioxidants than any other fruit. And for all the fiber a cup of blueberries packs — 14% of your recommended daily value — it only has around 85 calories.
Cucumbers
A fruit that is mostly made up of water, cucumbers only contain 16 calories per serving. The seeds and skin contain most of the fruit’s nutritional value, so you’re best off not peeling your cucumbers.
The peel and seeds provide both fiber and a form of vitamin A known as beta-carotene, which is known to be good for your eyes.
Tomatoes

And for all the nutrients it boasts, one medium-sized tomato only has around 25 calories.