Can You Drink Apple Cider Vinegar While Fasting?
Apple cider vinegar is a grey area on a strict fast: no fasting trial tested it. What a review found on blood sugar and weight, and who should ask a clinician first.
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- Blimbi Editorial
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In 30 seconds
Apple cider vinegar is a grey area on a strict fast. It wasn’t among the energy-free drinks that fasting trials allowed, and none tested it, so on a zero-calorie fast, keep it for your eating window. The evidence behind its blood sugar and weight claims is weak.
- Fasting trials allowed energy-free drinks such as black coffee and tea; apple cider vinegar wasn't one of them.
- ACV gummies or drinks with sugar, juice or honey add energy and end a strict fast.
- A 2020 systematic review judged the evidence for apple vinegar's health effects insufficient.
- If you have diabetes or take glucose-lowering medicines, plan any fast with your clinician.
Does apple cider vinegar break a fast?
On a strict fast, treat it as a grey area. The trials behind this guide asked people to avoid all calories during the fast and allowed water and energy-free drinks such as black coffee, tea and diet soda. Vinegar wasn’t on that list, and no fasting trial cited here tested it. If your fast is a strict zero-calorie one, the simplest choice is to keep apple cider vinegar for your eating window.
In a 12-month randomized trial of eating only between noon and 8 p.m., participants were encouraged to drink plenty of water during the 16-hour fast and were allowed energy-free drinks such as black tea, coffee and diet sodas.Source 1
In the 12-week TREAT trial, the time-restricted group was told to eat from noon to 8 p.m. and to completely abstain from caloric intake for the rest of the day.Source 2
| Item | Breaks the fast? | Context |
|---|---|---|
| Apple cider vinegar diluted in water | It depends | Not tested in fasting trials, and not one of the energy-free drinks they allowed. On a strict zero-calorie fast, keep it for your eating window.Source 1 |
| ACV gummies or drinks with sugar, juice or honey | Yes | Sugar, juice and honey provide energy, so they end a zero-calorie fast. |
What does the evidence say about apple cider vinegar?
Less than the headlines suggest. Apple cider vinegar is often promoted for blood sugar control and weight loss, but the human research is limited, and none of it looked at vinegar during a fast.
A 2020 systematic review of 13 human and 12 animal studies found that apple vinegar may have beneficial health effects, but concluded that the evidence is insufficient because high-quality research is lacking, and called for larger, long-term trials.Source 3
| Claim | What the evidence shows |
|---|---|
| It keeps you fasted | Not tested; not on the trials' energy-free list |
| It lowers blood sugar | Possible benefits; the review found the evidence insufficient |
| It helps you lose weight | Not established; the evidence is insufficient |
| It detoxes the body | No source in this guide supports it |
Early evidence
No fasting trial has tested vinegar
Evidence on apple cider vinegar comes from a limited set of studies outside a fasting context, and the review authors called for larger, longer trials. None of the sources here shows that vinegar extends a fast, speeds up fat loss or cleanses the body.Source 3Source 1
If you take it, how should you take it?
If you want to try it, your eating window is the simplest place for it. Follow the label rather than taking more, because the evidence on side effects only covers recommended use.
The same review judged the risk of side effects inconsiderable when apple vinegar is taken in recommended quantities and in recommended ways.Source 3
Who should be careful with apple cider vinegar?
Frequently asked questions
Talk to a qualified health professional before fasting if you are pregnant or breastfeeding, under 18, living with or recovering from an eating disorder, have diabetes, take insulin or a medicine affected by meal timing, are an older adult, or are acutely ill. Do not change the dose or timing of any medicine without your clinician. See Blimbi’s safety guide.
Frequently asked questions
Does apple cider vinegar break a fast?
It's a grey area. Fasting trials allowed energy-free drinks such as black coffee and tea, and vinegar was neither on that list nor tested. On a strict zero-calorie fast, keep it for your eating window.Source 1
Does apple cider vinegar help you lose weight while fasting?
The evidence doesn't show it. A 2020 systematic review found the research on apple vinegar's effects on metabolism and body weight insufficient to draw conclusions, and no study cited here tested it during a fast.Source 3
Can you take ACV gummies while fasting?
Check the label. If they contain sugar, they add energy and end a strict fast; fasting trials such as TREAT asked participants to avoid all caloric intake during the fast.Source 2
Sources
Time-Restricted Eating Without Calorie Counting for Weight Loss in a Racially Diverse Population: A Randomized Controlled TrialShuhao Lin et al. American College of Physicians, July 1, 2023.DOI: 10.7326/M23-0052 · PMID: 37364268Human randomized trial
Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters in Women and Men With Overweight and Obesity: The TREAT Randomized Clinical TrialDylan A. Lowe et al. American Medical Association (AMA), November 1, 2020.DOI: 10.1001/jamainternmed.2020.4153 · PMID: 32986097Human randomized trial
Safety and side effects of apple vinegar intake and its effect on metabolic parameters and body weight: a systematic reviewTine Louise Launholt, Christina Blanner Kristiansen, Peter Hjorth. Springer Science and Business Media LLC, September 1, 2020.DOI: 10.1007/s00394-020-02214-3 · PMID: 32170375Systematic review and meta-analysis
Fasting Safely with DiabetesMartin M. Grajower. National Institute of Diabetes and Digestive and Kidney Diseases, August 26, 2020.Official guidance