Can You Drink Tea While Fasting? Green, Black and Herbal
Yes: plain black, green and herbal tea add essentially no energy while fasting. See which additions end the fast and how much caffeine tea adds.
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Plain tea fits a fast. Black, green, white and oolong tea and herbal infusions add no energy; one 12-month trial allowed black tea. Milk, sugar, honey and sweet bottled teas end a strict fast.
- A 12-month trial allowed black tea among energy-free drinks.
- Milk, sugar, honey and sweet teas add energy and end a strict fast.
- Black or green tea has about 75 mg of caffeine per cup; it adds up.
- In pregnancy, NHS guidance caps caffeine at 200 mg a day and suggests no more than four cups of herbal tea.
Does tea break a fast?
Not if it’s plain. The fasting trials behind this guide count energy, not flavour, and tea brewed only with water counts as an energy-free drink. What you stir into the cup decides whether the fast continues.
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
| Item | Breaks the fast? | Context |
|---|---|---|
| Black, green, white or oolong tea, no milk | No | Brewed only with water, tea is treated as an energy-free drink; it does contain caffeine.Source 1 |
| Plain herbal infusion | No | Leaves, flowers or roots steeped in water add essentially no energy. Check the label: some blends include sugar, sweeteners or dried fruit. |
| Tea with milk | Yes | Milk contains fat, protein and milk sugar, so even a splash adds energy.Source 5 |
| Tea with sugar or honey | Yes | Sugars provide energy, so the fast ends. |
| Chai or matcha latte, bubble tea, sweet iced tea | Yes | Usually made with milk, sugar or syrup; treat them as food, not as a fasting drink. |
How much caffeine is in tea?
It depends on the tea. Black, green, white and oolong teas contain caffeine, while most plain herbal infusions don’t. For healthy adults, what matters is the total across the day.
NHS estimates about 75 mg of caffeine in a cup of black or green tea, compared with about 100 mg in a cup of instant coffee.Source 4
A systematic review concluded that up to 400 mg of caffeine a day is generally not associated with overt adverse effects in healthy adults.Source 6
| Tea | Caffeine |
|---|---|
| Black or green tea | About 75 mg per cup (NHS estimate) |
| White or oolong tea | Contains caffeine; the amount varies |
| Yerba mate | Contains caffeine |
| Peppermint, chamomile or rooibos | Usually caffeine-free |
If your fast starts in the evening, switching to a caffeine-free infusion after lunch keeps the ritual without the late caffeine.
A meta-analysis of 24 studies found that caffeine reduced total sleep time by about 45 minutes on average and increased the time needed to fall asleep.Source 7
What can tea do during a fast?
It adds warmth and flavour without energy, and it counts toward the fluids you need anyway. That’s the real benefit.
NHS guidance counts water, lower-fat milk and sugar-free drinks, including tea and coffee, toward daily fluid intake and suggests about 6 to 8 cups or glasses of fluid a day as a general guide.Source 3
Early evidence
Tea-specific fasting research is scarce
Evidence on tea during a fast comes from trial rules, not tea studies: a 12-month trial allowed black tea during the 16-hour fast but did not measure whether tea changed any outcome. These sources do not support claims that a tea speeds up fat loss or cleanses the body.Source 1
Who should be careful with tea?
Frequently asked questions
Coffee works the same way; see coffee during intermittent fasting.
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 green tea break a fast?
Not if it's plain. Unsweetened green tea brewed with water is an energy-free drink, like the black tea allowed in a 12-month fasting trial. It does contain caffeine, about 75 mg per cup by NHS estimates.Source 1Source 4
Can you drink herbal tea while fasting?
Yes. Plain herbal infusions add essentially no energy, so they fit most fasting windows; check labels for added sugar or fruit. During pregnancy, NHS guidance suggests no more than four cups of herbal tea a day and avoiding liquorice root.Source 4
Does tea with milk break a fast?
Yes, in a strict sense. Milk contains fat, protein and milk sugar, and fasting trials such as TREAT asked participants to avoid all caloric intake outside the eating window.Source 5Source 2
Does tea count toward your water intake?
Yes. NHS guidance counts sugar-free drinks, including tea and coffee, toward your daily fluid intake. Plain water is still a simple choice, and pale-yellow urine is a practical sign you are drinking enough.Source 3
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
Water, drinks and hydrationNHS. NHS, May 17, 2023.Official guidance
Foods to avoid in pregnancyNHS. NHS, June 15, 2026.Official guidance
Dairy and alternatives in your dietNHS. NHS, December 11, 2023.Official guidance
Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and childrenDaniele Wikoff et al. Elsevier BV, November 1, 2017.DOI: 10.1016/j.fct.2017.04.002 · PMID: 28438661Systematic review and meta-analysis
The effect of caffeine on subsequent sleep: A systematic review and meta-analysisCarissa Gardiner et al. Elsevier BV, June 1, 2023.DOI: 10.1016/j.smrv.2023.101764 · PMID: 36870101Systematic review and meta-analysis
Fasting Safely with DiabetesMartin M. Grajower. National Institute of Diabetes and Digestive and Kidney Diseases, August 26, 2020.Official guidance