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Celery has negative calories: you burn more chewing it than it contains.
Celery is the poster food for a claim that has never been measured in anyone. The arithmetic below uses the most generous digestion cost ever recorded for a whole food and celery still comes out positive.
Verdict: Falsecelery negative caloriescelery dietthermic effect of celery
The claim, as people state it
“Celery has negative calories: you burn more chewing it than it contains.”
What is actually known
Celery is roughly 95% water by weight, which is why its energy content per 100 g is among the lowest of any food in the database. That is the entire basis of the myth: the number is so small that it feels like it could round through zero into negative. It does not.
The energy cost of processing a food is a percentage of what it carries, and for a watery, fibrous, carbohydrate food that percentage sits at the low end — well under a third. Chewing adds a genuinely measurable but tiny amount on top; studies of chewing energy expenditure put it at a few calories per hour of chewing, and nobody chews celery for an hour.
Nobody has ever demonstrated a negative net energy for celery, or for any food. The claim circulates entirely without a measurement behind it, which is unusual even by the standards of diet folklore.
There is a smaller, more defensible version of the idea buried in here, and it is worth separating out. Celery is high in insoluble fibre, and fibre yields less usable energy than the four-calories-per-gram carbohydrate figure on a label assumes — some passes through, some is fermented by gut bacteria at a lower yield. So the true net energy of celery is probably a little below its listed value. A little below fourteen is still comfortably above zero, and that correction is measured in single calories, not in a change of sign.
Why the myth persists
Because the practical advice is excellent and the explanation is memorable. Celery genuinely is a near-free food, and telling someone "eat as much as you like" is true. The negative-calorie framing is just a more exciting way of saying "almost zero", and more exciting versions win.
The arithmetic
Celery carries 14 kcal per 100 g. A single 40 g stalk is 5.6 kcal — you would need about 18 stalks to reach the energy in one plain biscuit. Now charge it for digestion at three different rates:
| Thermic effect applied | Cost per 100 g | Net kcal per 100 g | Sign |
|---|---|---|---|
| 10% (a mixed diet) | 1.4 | 12.6 | positive |
| 20% (high-protein food) | 2.8 | 11.2 | positive |
| 30% (the highest ever measured) | 4.2 | 9.8 | positive |
The sign never flips. To reach zero, the digestion cost would have to be 100%; to go negative it would have to exceed it. And the chewing that the myth relies on is worth a few calories an hour — you would have to chew celery continuously for hours to spend the 5.6 kcal in a single stalk.
Meanwhile a 15 g smear of cream cheese on top adds 53 kcal — about 9 stalks' worth of celery, sitting on one of them.
Every figure in this section was computed when this page loaded, from 5 237 food rows and 31 exercise rows already in this repository. Nothing in it is stored as prose.
The honest nuance
Celery is a good tool for exactly the reason the myth gestures at. Its volume per calorie is extraordinary, and volume is what makes a meal feel like a meal. Use it as a filler, not as a subtraction.
What goes on the celery is usually where the calories are. Peanut butter, cream cheese and blue cheese dip each carry more energy in a tablespoon than a whole stick of celery carries in total.
General information, not a diagnosis and not medical advice. Anything touching a condition you have, a medicine you take or a test result belongs with your own clinician, who has information no web page does.
Frequently asked questions
Is celery still worth eating on a diet?
Yes, and for the reason the myth points at, if not the reason it states: enormous volume for almost no energy, plus fibre and water.
Does chewing burn a meaningful number of calories?
No. Chewing energy expenditure has been measured and comes out at a few calories per hour of continuous chewing.
Source: USDA FoodData Central (SR Legacy) via the TempoLife food database; MET values from the 2011 Compendium of Physical Activities · checked 2026-09-02
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