Yes, during intermittent fasting you can drink plain tea and black coffee; skip milk, sugar, and creamers to keep the fast.
Fasting windows feel easier when you know exactly what’s allowed. Plain tea and black coffee are the go-tos because they add almost no calories, keep hydration on track, and can blunt appetite for some people. The catch: once you pour in milk, cream, syrups, or sugar, you’ve moved out of a true fasting window and into a mini-meal. This guide lays out what’s fine, what to avoid, and simple ways to use tea or coffee without derailing your plan.
Tea And Coffee During A Fasting Window: Simple Rules
Most fasting styles (16:8, 18:6, alternate-day, OMAD) treat water, unsweetened tea, and black coffee as fair game during the no-food stretch. Johns Hopkins Medicine states that zero-calorie beverages like black coffee and tea are permitted during the fasting period, which matches the approach used in many clinical protocols (Intermittent fasting overview). Below you’ll find a quick matrix of common drinks and whether they fit a strict fasting window.
Quick Drink Matrix For A Fast
| Drink | Typical Calories (8 oz) | Fasting Window Friendly? |
|---|---|---|
| Water (Still Or Sparkling) | 0 | Yes |
| Black Coffee | ~2 | Yes |
| Unsweetened Tea (Green/Black/Herbal) | 0–2 | Yes |
| Americano (No Milk) | ~5 | Usually Yes* |
| Cold Brew (Plain) | ~2 | Yes |
| Espresso (1 oz) | ~3 | Yes |
| Coffee With Milk Or Cream | 7–50+ | Limit/Avoid |
| Coffee With Sugar Or Syrup | 16–100+ | No |
| Tea With Honey | 20–60+ | No |
| Diet Soda / “Zero” Drinks | 0 | Use Sparingly** |
| Bone Broth | 30–60 | No (Strict Fast) |
| Energy Drinks (Even “Sugar-Free”) | 0–15+ | Use Sparingly** |
*A pure espresso-and-water drink is fine for most people. If your plan is strict to the letter, keep it plain and skip flavor shots. **Noncaloric sweeteners don’t add energy, but they can trigger cravings or stomach upset for some.
What “Breaks A Fast” In Practice
A strict fasting window means no calories. That’s the cleanest definition used in research settings. In day-to-day life, many people tolerate one or two calories from black coffee or plain tea and still see the results they want. The trouble starts with add-ins that quietly turn into real energy.
Add-Ins That End A Strict Window
- Milk, cream, half-and-half, creamers: dairy or plant-based, they supply energy and shift you out of a true fast.
- Sugar, honey, syrups: even a teaspoon pushes insulin up and changes the whole point of the fasting stretch.
- Butter/MCT/coconut oil: popular in some circles, but they’re pure energy and not part of a strict window.
Some flexible plans allow small amounts of fat during the no-food period. If you’re using fasting for blood sugar control or weight loss with tight targets, keep the window clean and enjoy all add-ins during your eating period instead.
Brew Choices That Keep The Window Clean
Black Coffee, Hot Or Iced
A standard 8-ounce cup of brewed coffee sits around two calories. That’s close enough to zero for most fasting routines. Choose a roast you like, grind fresh if you can, and keep it plain.
Tea Without Sweeteners
Green, black, oolong, white, rooibos, hibiscus, and plain herbal blends bring flavor with negligible calories. Skip dessert-style blends with dried fruit pieces or stevia-based sweetener packets if you notice cravings after drinking them.
What About Cold Brew Or Americano?
Cold brew concentrates taste smoother and often feel stronger. When diluted to a typical glass, the energy content is still near zero. An Americano (espresso plus water) is also near zero as long as you don’t add milk or syrups.
How Caffeine Fits Into A Fasting Day
Caffeine can sharpen focus and tame appetite. It can also cause jitters, reflux, or sleep trouble if you overdo it. The U.S. Food and Drug Administration lists 400 mg per day as a level not generally linked to negative effects for most healthy adults; that’s about four small mugs, depending on brew strength (FDA caffeine guidance).
Smart Caffeine Habits While Fasting
- Cap the total: aim for no more than 400 mg in a day unless your clinician tells you otherwise.
- Front-load earlier: keep caffeine away from the last 8–10 hours before bed so sleep stays solid.
- Watch the empty-stomach effect: if coffee alone makes you shaky or sour, switch to tea or dilute it.
- Skip powders and “pure” caffeine: bulk products are easy to mismeasure and risky.
Flavor Moves That Don’t Break Your Window
Plain drinks get free-pass status. Still, you can add a little flair without drifting into a snack.
Zero-Calorie Additions
- Cinnamon stick or ground spice: adds aroma to coffee or tea with no sugar.
- Vanilla bean or extract splash: a few drops can lift a cold brew. Use a light hand.
- Lemon slice in tea or water: bright flavor, near zero energy.
- Plain soda water topper: half coffee, half sparkling for a café tonic vibe, no syrup.
Low-Impact Techniques
- Ice and dilution: turn a strong brew into a longer sip to stretch the fast.
- Light roast vs. dark roast: choose taste, not myths; caffeine varies more by brew ratio than roast color.
When Tea Or Coffee Might Not Be Your Best Move
Some folks feel queasy, anxious, or wired during the window, especially in the morning. If that’s you, swap part of your intake for water or herbal blends with little to no caffeine. People with reflux, ulcers, or palpitations often do better limiting strong brews on an empty stomach.
Pregnant or nursing people need tighter limits, and anyone on medicines that interact with caffeine should follow medical advice tailored to their case. Fasting is optional; if it complicates your routine or sleep, use a gentle schedule or skip it.
Tea And Coffee Choices Across Popular Fasting Styles
Time-Restricted Eating (16:8, 18:6)
During the 16–18 hour no-food period, lean on water first. Add black coffee or plain tea for one to three cups spread across the morning and early afternoon. In the 8–6 hour eating period, enjoy milk lattes or sweetened tea if they fit your goals.
Alternate-Day Or 5:2 Patterns
On low-energy days, plain tea and black coffee curb appetite and make the low-calorie target easier. On regular days, there’s room for your usual café order.
OMAD (One Meal A Day)
Use unsweetened drinks to get through the long window. Save any flavorful add-ins for the single meal so you’re not white-knuckling the fast.
Keeping Hydration On Track
Dehydration feels a lot like hunger. Tea and coffee contribute to daily fluids, and the mild diuretic effect isn’t a problem for most people when intake is moderate. Pair each caffeinated drink with a glass of water. If your mouth feels dry or your energy dips, increase plain water first.
Side Effects To Watch During A Fasting Window
- Jitters, anxiety, or a racing heart: cut the dose, swap to tea, or push the next cup into your eating window.
- Acid reflux or stomach cramps: go with a gentler brew or a lighter roast; skip coffee until the meal window opens.
- Sleep disruption: end caffeine by mid-afternoon.
- Cravings after diet soda or sweetened “zero” drinks: switch to plain tea or water.
Brewing Tips For A Smoother Fast
Coffee
- Grind size and ratio: 1:15 to 1:17 coffee-to-water by weight makes a balanced cup without bitterness.
- Cold brew basics: 1:8 concentrate steeped 12–18 hours; dilute 1:1 or to taste with cold water.
- Instant done right: pick plain versions without added sugar or creamer blends.
Tea
- Time and temp: green likes cooler water (70–80°C) for 2–3 minutes; black sits well at a near boil for 3–5 minutes.
- Herbal options: mint, ginger, or rooibos bring flavor with minimal energy.
- Iced tea shortcut: brew double-strength hot tea over a full glass of ice.
Caffeine Snapshot For Popular Drinks
Numbers vary by brand, roast, grind, and brew method. Treat these as ballpark guides when planning your day.
| Beverage | Typical Caffeine (8 oz*) | Notes |
|---|---|---|
| Brewed Coffee | ~95 mg | Strength swings with ratio and grind. |
| Cold Brew | ~100–150 mg | Often stronger per ounce before dilution. |
| Black Tea | ~40–60 mg | Steep time changes the range. |
| Green Tea | ~20–45 mg | Lower than most coffees per serving. |
| Espresso (1 oz*) | ~60–75 mg | *Shot size listed; not 8 oz. |
| Herbal Tea | 0 mg | Check blends with added mate or guayusa. |
Putting It All Together
During the no-food stretch, stick to plain tea, black coffee, and water. Save milk, creamers, sweeteners, and syrups for the eating window. Keep total caffeine in a sensible range and front-load it earlier in the day. If you feel wired or queasy, swap to gentler brews or reduce the dose. If your doctor has given you limits for caffeine or asked you to change your fasting plan, follow that guidance first.
Why This Approach Works
Plain tea and black coffee bring flavor and ritual without adding energy. That keeps the fasting period aligned with the goal of reducing energy intake across the day. Clinical summaries from academic centers endorse zero-calorie drinks during the fasting window, and federal guidance sets a sensible ceiling for daily caffeine intake. If your personal plan uses a different rule set, use that rule set; consistency matters more than chasing someone else’s template.
Simple Sample Day (16:8)
Morning (Fasting Window)
- Wake: water first.
- Two hours later: black coffee or plain tea.
- Late morning: another cup if you like, or switch to herbal.
Eating Window Opens
- Break with a balanced meal.
- Enjoy milk coffee or sweetened tea if it fits your plan.
- End caffeine by mid-afternoon to keep sleep on track.
Evening (Back To Fasting)
- Plain water or herbal blends only.
- Shut down the kitchen on schedule.
Key Takeaways You Can Use Today
- Yes, plain tea and black coffee fit a fasting window.
- Add-ins end a strict window. Keep the fun drinks for the eating period.
- Mind the total caffeine. The FDA sets 400 mg per day as a practical ceiling for most adults.
- Sleep beats one more cup. Stop caffeine early enough so you actually feel the benefits of your plan.
References for readers who want more detail: see the Johns Hopkins overview of intermittent fasting and the FDA’s consumer guidance on caffeine linked above.