It would be great if we lived in a world where all the food we really loved eating contained absolutely no calories.

Unfortunately, that kind of utopia doesn’t exist yet, but it’s not all bad. There are definitely plenty of foods you can really enjoy digging into without having to worry that you’ll be piling on the pounds as a result.

Here are 20 foods to help you lose weight, and the science behind why:

Nutritionist Dr. Lisa Young explains that such low-calories foods usually fall into either of these two categories: vegetables and non-starchy fruits. And why do we not gain weight after eating these kinds of foods? Well, because they’re usually made up of water, plenty of nutrients and they contain fiber, which helps you feel fuller for longer.

So, without further ado, here are 14 foods you can eat to your heart’s content and not have to worry about weight gain.

1. Kale

Kale is very low in calories – in fact, a whole cup of raw kale contains a minuscule 33 calories. However, in spite of its low-calorie content, it contains almost three grams of protein and 2.5 grams of fiber per serving. It also contains rare and healthy nutrients such as omega-three fatty acids, which a lot of people assume you can only get from fish. It’s also high in folate and vitamins.

2. Blueberries

One of the healthiest things about blueberries is their high antioxidant content. Fun fact: blueberries have more antioxidants than any other fruit. Plus a cup of blueberries contains 14% of your recommended daily fiber intake and only contains about 85 calories.