Celery is probably the most notorious "negative-calorie" food (that’s not actually a thing, by the way). What’s meant by the commonly used term? There's this thing called the 'thermogenic effect of food'—in short, your body burns calories digesting the food you eat. But it really varies by person and genetics. So, yes, it could take more energy to digest than you’re actually getting from the veggie, which is where its reputation as a negative- or zero-calorie food comes from.
Calories per medium pepper: 30

Slice them up into sticks; throw them into a stir-fry; or hollow them out, stuff with lean ground beef and couscous, and bake. However you prefer to eat them, just be sure to get these flavorful veggies into your diet STAT.
3. Kale
Calories per cup, chopped: 33

Kale has found its way onto every healthy-food list, and it would be wrong to leave it off of this one. We find that people who have a low intake of these types of vegetables have higher body weights consistently. People who say they don’t like vegetables don’t realize they’re putting themselves at risk, because incorporating these foods tends to naturally lower total caloric intake for the day.
4. Broccoli
Calories per cup, chopped: 31

Cruciferous vegetables are the mainstay when it comes to “zero-calorie” foods, and broccoli is one of the best ones for you. Its deep green hue is a dead giveaway that it’s full of cancer-fighting phytochemicals. Broccoli is also packed with gut-filling fiber. Foods that are high in fiber are typically the ones that are going to make you feel full longer. Eat it raw or steam a large portion for a filling snack or side.
5. Purple Cabbage
Calories per cup, chopped: 22

Every food hue offers some kind of anti-cancer benefits. When it comes to purple veggies, you always think of heart health and a lot of cardiovascular benefits. While you probably won’t be biting into a whole cabbage, cut off a big chunk and toss it into salads or stir-fries. The addition will make your meal more filling and help curb the need to snack as the day goes on.
6. Cauliflower
Calories per cup, chopped: 27

We’re aware that you probably don’t crave cauliflower, per se, but when you’re in the mood to snack, this is a smart option. If you’re not so keen on the taste of raw cauliflower, you can make it taste wonderful with some olive oil, but every teaspoon adds about 45 calories. I recommend steaming cauliflower and flavoring it with herbs and spices or a little lemon zest.
7. Cherry Tomatoes
Calories per cup: 27

This is the only "fruit" you’ll see on this list. In general, fruit has about 60 calories per serving—so more than double the calorie content of non-starchy vegetables. But tomatoes are on the lower end of the fruit calorie spectrum, so forgo grapes every now and then and pop cherry tomatoes into your mouth for a healthy, lower-sugar snack.
8. Spinach
Calories per cup: 7

Leafy greens are always a safe bet. Aside from being very low in calories, spinach will benefit your body tremendously, especially if you’re working out intensely. When we're breaking down muscle at the cellular level, we have to re-nourish our bodies with the proper foods. Your body is going to repair itself in the most optimal way when you’re eating greens.