Is zero calorie food possible?

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Short answer:
  • The theory behind zero (or negative) calorie food is that the body would consume more energy to digest them.
  • There is no scientific evidence that these exist, although many foods have close to zero calories (e.g., lettuce).
  • The only genuinely zero-calorie meal or beverage that exists is water. However, the FDA permits the identification of anything with fewer than five calories as being zero-calorie.

This article may contain allegations about zero/negative-calorie food which may not be evidence-based. You can improve this article by editing it.

Calories in food refer to how much energy a unit of food supplies, and the most basic measure of food quantity is the calorie count, so to a first approximation, someone who has eaten a zero-calorie substance has not eaten any food.

Zero-calorie foods are characterized by a high water and fiber content and a low-fat level. Although the validity of zero-calorie meals has been heavily contested, no scientific research has examined the authenticity of zero-calorie foods.

But organisms also need a steady supply of certain chemicals, whether they provide energy or not, such as vitamins and water, to live and grow. Vitamins typically provide virtually no energy when digested and may even absorb energy, so somethicontainingins vitamins could be zero-calorie.

We take in calories when we eat and expend calories when we burn energy. The only genuinely calorie-free meal or beverage is water. Why, then, do so many goods claim to have no calories? The FDA legally permits manufacturers to identify anything with fewer than five calories as being zero calories.[1]

Water, a zero calorie beverage

Although using these foods in the diet is perfectly acceptable because they are rich in vitamins and nutrients that contribute to a healthy profile, relying only on them to lose weight is erroneous and illogical. The idea behind these supposedly calorie-free or "negative calorie" foods is that digestion increases calorie expenditure.[2]

While not a foodstuff, cold water is claimed to have no calories, while consuming water outside of the body's normal temperature ranges will require some energy expenditure to maintain body temperature, this is known as the "water-induced thermogenesis effect."[3]

Scientific research about zero-calorie food[edit]

Zero-calorie food is more related to positive energy gained against negative energy. The two points to consider:

  • After accounting for the projected energy consumed during chewing, digestion, and absorption, as well as the energy lost through excretion, all suggested negative-calorie meals may yield a net gain in energy

However, it is essential that this gain only reflects the pluses and minuses associated with a meal's digestion and absorption, and does not account for additional metabolic expense.

  • The extent to which this increase supports other metabolic expenditures.[4]

What will happen if someone just relies low calorie foods?[edit]

Here are the adverse effects of consuming insufficient calories on the body:

  • Slowing of the metabolism
  • Possibly lead to nutrient deficiencies
  • Diminished immunity
  • Bone weakening[5]

Conclusion about zero-calorie food[edit]

Anyone will gain some energy from the celery they ate, but the amount of energy they got was extremely little in terms of how much it contributed to their daily energy expenditure. The ingestion of such meals would encourage a daily negative energy budget, which will lead to weight reduction through the catabolism of body fat. Rather than identifying such foods as "negative calorie," it would be more correct to sell these foods as "negative budget."[6]


  1. Boston, 677 Huntington Avenue; Ma 02115 +1495‑1000 (2019-09-24). "Water". The Nutrition Source. Retrieved 2022-10-31.
  2. "Mythbuster: Negative Calorie Foods". Food Insight. 2016-10-11. Retrieved 2022-10-31.
  3. "Does Metabolism Matter in Weight Loss?". Harvard Health. 2015-07-16. Retrieved 2022-10-31.
  4. Ashraf, Rahbika; Duncan, Alison M.; Darlington, Gerarda; Buchholz, Andrea C.; Haines, Jess; Ma, David W. L. (2022). "The degree of food processing is associated with anthropometric measures of obesity in Canadian families with preschool-aged children". Frontiers in Nutrition. 9. doi:10.3389/fnut.2022.1005227/full. ISSN 2296-861X.
  5. "35 Simple Ways to Cut Lots of Calories". Healthline. 2019-04-23. Retrieved 2022-10-31.
  6. Zeballos, Eliana; Chelius, Carolyn (2021). "The effects of grazing on daily caloric intake and dietary quality". International Journal of Behavioral Nutrition and Physical Activity. 18 (1). doi:10.1186/s12966-021-01226-4. ISSN 1479-5868. PMC 8684066 Check |pmc= value (help). PMID 34922578 Check |pmid= value (help).