Negative-Calorie Food: Fact or Fantasy?

Wouldn’t it be nice to eat as much as you wanted of certain foods—and actually lose weight just from eating them?! Umm, yes! Before I break down whether these miracle goodies actually exist, let me give you a little background.

What is the negative-calorie food theory?

The negative-calorie food theory is based around the idea that the body uses energy to digest and process foods. The theory suggests that some foods cause the body to burn more calories than they actually contain. Finally, math sounds fun!

Negative-calorie foods include celery, cabbage, garlic, and leafy greens, all of which have very few calories to begin with.

Does the body use energy to digest food?

Yes, absolutely. People use about 10% of their daily caloric expenditure (in other words, how many calories we burn on a daily basis) digesting food. This process is often referred to as the thermic effect of food (TEF).

It takes energy to chew, swallow and digest. But don’t break out the bubbly just yet! You shouldn’t suddenly add 10% more calories into your metabolic life because you now know about it. Your body has been doing this, always.

Of the three major macronutrients, protein has the highest TEF, meaning it burns the most calories during digestion. Carbs rank second. Taking the bronze medal (you could’ve guessed this, right?) is fat. BTW, if you need another reason to eat whole foods instead of processed ones, research shows the TEF of processed meals and snacks is about 50% less than that of whole foods. There you have it, an apple beats a Pop-Tart again!

How healthy are these negative-calorie foods?

So, what exactly are the nutritional profiles of these alleged miracle foods? Let’s check them out! As you’ll see, they all do contain calories.


Let’s begin with an all-star on this list: One cup of chopped broccoli provides plenty of nutrition for its 31 calories. You get 6 grams of carbs, 2.6 grams of protein and only 0.3 grams of fat. You’ll also get 2.4 grams of fiber and almost your entire daily allowance of vitamin C (81.2 micrograms) and vitamin K (92.5 micrograms).


This cruciferous vegetable packs more nutrition into a serving—along with more calories, of course. One cup of chopped cabbage yields 22 calories; only 0.1 gram of fat, along with 1.1 grams of protein and 5.2 grams of carbs. You’ll also get 2.2 grams of fiber and 2.8 grams of sugar, plus a significant amount of vitamin C (32.6 micrograms) and vitamin K (67.6 micrograms).


One 12-inch stalk of celery contains a mere 9 calories. It doesn’t contain much in the way of macronutrients: negligible amounts of protein (0.4 grams) and fat (0.1 grams); carbs clock in at 1.9 grams. You’ll also get 1 gram of fiber. Its biggest nutrient is vitamin K, of which you’ll get 18.8 micrograms per stalk.


Although botanically classified as a fruit, we all think of cucumber as a vegetable. It provides lots of hydration, of course, and 16 calories in a one-cup serving. You’ll also get 3.8 grams of carbs, 0.7 grams of protein and just 0.1 grams of fat. Like several other usual suspects on the “negative-calorie” list, cucumber’s biggest nutrient, rated proportionally, is vitamin K: 17.1 micrograms.


One clove of garlic packs a ton of flavor, but not much else! It only has 4 calories, attained from 1 single carbohydrate gram, 0.2 grams of protein and zero fat.


This citrus star is a heavy hitter, nutritionally speaking. With just 74 calories per one-cup serving (grapefruit sections plus juice), you get 18.6 grams of carbs, 1.4 grams of protein and a mere 0.2 grams of fat. Meanwhile you get 2.5 grams of fiber, 16.1 grams of natural sugars and 105.8 micrograms of vitamin A. Of course, it’s a major source of vitamin C, clocking in at 79.1 micrograms (basically the entire amount of an adult’s recommended daily allowance).

Should I be eating negative-calorie foods?

Did it sound too good to be true? That’s because it is. However great this theory may sound, there is no scientific proof that it’s an effective way to diet.

With that said, should you be incorporating whole, real foods into your meals that also have the reputation to be negative-calorie foods? Why, yes. But that’s because they’re packed with vitamins, minerals, water, fiber and/or protein, not because they might have “negative calories.” According to a study published in 2019, these foods still help with weight loss, provided you eat them in place of higher-calorie dishes.

Eat up the celery, cabbage, grapefruit, cucumber and broccoli because they’re good for you. They really do help you manage your weight—and they’re loaded with nutrients.

(Image: Shutterstock)

About Nutritious Life Editors

The Nutritious Life Editors are a team of healthy lifestyle enthusiasts who not only subscribe to — and live! — the 8 Pillars of a Nutritious Life, but also have access to some of the savviest thought leaders in the health and wellness space — including our founder and resident dietitian, Keri Glassman. From the hottest trends in wellness to the latest medical science, we stay on top of it all in order to deliver the info YOU need to live your most nutritious life.

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