I've been doing 16:8 intermittent fasting most weekdays for about two years now. The question I get asked most often about it — more than "does it work?" or "don't you get hungry?" — is "can you drink tea while fasting?" The answer is simple. Yes. I do it every morning. But there are a few details worth knowing, especially if you're choosing between different teas during your fasting window.
Why tea doesn't break a fast
A metabolic fast is maintained as long as you don't consume enough calories to trigger an insulin response. The threshold is debated, but most researchers and practitioners agree that anything under 5 calories is negligible. A cup of plain-brewed tea — regardless of type — contains less than 2 calories. No insulin spike, no broken fast.
What tea does do during a fast is provide caffeine and L-theanine, which many fasters find helpful for sustaining energy and focus through the morning without food. The combination gives you alertness without the cortisol spike that some people experience from black coffee on an empty stomach.
Best teas during a fasting window (ranked)
1. Oolong tea — my fasting go-to
Oolong sits at 30–60 mg caffeine per cup — enough to keep you sharp, not enough to make you jittery. The L-theanine smooths out the caffeine edge. I drink Peach Mountain ($21.50/$19.50) or Sakura Blossom ($21.50/$19.50) during my fasting window most mornings. The real-fruit scenting adds flavour without adding measurable calories — the amount of sugar from dried peach or cherry blossom in a brewed cup is trace at best.
2. Black tea — the coffee replacement
If you're coming to IF from a coffee-heavy background and want to reduce coffee without losing the caffeine, black tea is the bridge. Coffee or Tea ($22.50/$19.50) is our caffeinated black tea specifically designed for this moment — it delivers a caffeine kick closer to coffee but with the smoother absorption profile of tea. Zero calories in the cup.
3. Green tea — EGCG bonus during the fast
Some IF practitioners specifically choose green tea for fasting windows because EGCG may compound the fat-oxidation benefits of the fasted state. The evidence for this specific combination (fasting + green tea) is limited — most EGCG studies didn't test in fasted subjects — but the logic is plausible and the downside is zero. Just watch your stomach: green tea on a completely empty stomach can cause nausea for some people. If that's you, try a Chinese green like Gardenia Moonlight ($21.00/$19.00), which is gentler than Japanese sencha.
4. Pu-erh — for the late-morning hunger pangs
Aged shou pu-erh has a thick, almost broth-like mouthfeel that psychologically helps with hunger during the last hours of a fasting window. It feels like you're drinking something substantial even though the calorie content is negligible. Our Pu-erh Delight ($35.50) adds citrus aroma from the tangerine shell, which makes it feel even more "food-like" without being food.
What to avoid during a fast
- Milk or cream in tea — even a splash adds 10–20 calories and triggers a small insulin response. Save it for your eating window.
- Sugar, honey or sweeteners — sugar and honey definitely break a fast. Artificial sweeteners are debated; some may trigger an insulin response despite being zero-calorie. The safest approach: plain tea only.
- Bubble tea or chai latte — obviously not fasting-compatible. These are desserts in cup form.
- Herbal "teas" with dried fruit pieces — some fruit teas contain enough dried fruit to contribute 5–10 calories per cup. Check the ingredients if you're strict.
What about our Xiao Qing Gan range?
Honest answer: our Xiao Qing Gan teas (Tangerine Pu-erh, Tangerine Oolong, Tangerine White Tea, Tangerine Black Tea) steep with the tangerine shell, which may release trace natural sugars from the peel. We haven't lab-tested the exact calorie contribution, but it's almost certainly under 5 kcal per cup. For most IF practitioners, this is well within the negligible range. If you're very strict about zero-calorie fasting, use loose-leaf tea without the shell during your fast and save the Xiao Qing Gan for your eating window.
My fasting routine (what I actually do)
6:00 am: Wake up. Water.
7:00 am: First cup of oolong (Peach Mountain or Sakura Blossom). This is when the fast would feel hardest without something warm in my hands.
9:30 am: Second cup — usually Coffee or Tea if I need more focus for morning work, or a plain green tea if the day is calmer.
11:30 am: If I'm hungry, a cup of pu-erh. The thick mouthfeel tricks my brain into thinking I've had something substantial.
12:00 pm: Eating window opens. First meal. Usually followed by a cup of Xiao Qing Gan after eating (digestion support — see our digestion guide).
8:00 pm: Eating window closes. Evening gardenia tea (calming, low caffeine — see our sleep guide).
This routine has worked for me for two years. I'm not saying it's optimal or that it'll work for everyone. IF is very individual — some people thrive on it, others feel terrible. Tea makes it more tolerable, not magical.
FAQ
Does green tea break intermittent fasting?
No. Plain-brewed green tea has under 2 calories per cup. It doesn't trigger an insulin response. You can drink it throughout your fasting window.
Does tea with lemon break a fast?
A squeeze of lemon adds about 1–2 calories. For practical purposes, this doesn't break a fast. A whole lemon wedge squeezed into tea is fine.
Can I drink oolong tea while fasting?
Yes. Oolong is one of the best teas for fasting windows — moderate caffeine, L-theanine for calm focus, zero calories when brewed plain.
Is it better to drink tea or coffee during intermittent fasting?
Both work. Tea has the advantage of L-theanine (smoother alertness, less cortisol spike) and is gentler on an empty stomach. Coffee has more caffeine per cup. Some people alternate — coffee first thing, tea mid-morning. Personal preference.
For the full weight management guide, see Best Tea for Weight Loss in Australia. For evening teas after your eating window, see Best Tea Before Bed.
