Does Coffee Break a Fast? Coffee During Intermittent Fasting
Plain black coffee is generally considered compatible with intermittent fasting: it contains only a few calories and no meaningful sugar, fat, or protein. Milk, sugar, syrups, and larger amounts of cream or oil add calories and mean you are no longer strictly fasting. This page explains why, walks through common add-ins, covers caffeine limits and possible side effects, and gives simple timing examples for popular fasting schedules.
Table of Contents
- The Quick Answer: Does Coffee Break a Fast?
- Understanding What "Breaking a Fast" Means
- Black Coffee and Fasting
- Different Types of Coffee
- What Can You Add to Coffee?
- Why Coffee Can Help During Fasting
- Potential Drawbacks and Who Should Avoid
- Timing Your Coffee
- Practical Tips
- Alternative Beverages During Fasting
- Common Questions Answered
The Quick Answer: Does Coffee Break a Fast?
Short Answer: Black Coffee No, Most Add-Ins Yes
Black coffee (nothing added): generally does not break a fast
- A cup contains only a few calories
- It has no meaningful sugar, fat, or protein
- Research does not suggest it causes a meaningful insulin response on its own
- It is widely accepted within intermittent fasting practice
Coffee with add-ins: depends on what and how much
- Milk, sugar, syrups: these add calories and carbohydrate, so they break a fast
- Non-nutritive sweeteners: few or no calories; their effects on insulin and appetite are debated (see sweeteners and fasting)
- Butter, MCT oil, or cream in larger amounts: these add substantial calories, so you are no longer fasting, even if carbohydrate stays low
- Tiny amounts of some additions: a gray area that depends on your goals
It Depends Partly on Your Goal
People fast for different reasons, so the "rules" people apply to coffee differ:
Goal: A Strict or Longer Fast
Simplest choice: Black coffee or plain water
If you want to keep the fast as "clean" as possible, avoid anything with calories. Research on processes such as autophagy in humans is limited, so there is no precise calorie threshold known to matter.
Goal: Weight Management
Simplest choice: Black coffee; a small splash of milk or cream only if it genuinely helps you stick with your plan
Overall energy intake across the week matters most here. A few calories are unlikely to change results, but large creamy drinks add up.
Goal: Blood Sugar Control
Simplest choice: Black coffee without sugar
Avoid sugar and syrups. If you have diabetes or take glucose-lowering medication, talk to your healthcare provider before fasting.
Goal: Comfort
Simplest choice: Smaller amounts, or tea
Coffee stimulates the gut and can cause stomach upset on an empty stomach. If that happens, reduce the amount or try a gentler drink.
Understanding What "Breaking a Fast" Means
Whether something "breaks" a fast depends on how you define fasting. In the strictest sense, anything with calories ends a fast. In everyday intermittent fasting, most people use a practical definition: no meaningful calories, especially from sugar, protein, or fat, during the fasting window.
What Happens in the Body During a Fast
General Changes Over Several Hours Without Food
These changes happen gradually and vary with your last meal, activity level, and individual metabolism:
Insulin Falls
Without incoming food, especially carbohydrate, insulin levels decline. Lower insulin makes it easier for the body to release stored fat for energy.
Glucagon Rises
This hormone signals the liver to release stored glucose (glycogen) and, over time, to make new glucose from other sources (gluconeogenesis).
More Fat Is Used for Fuel
As liver glycogen falls, the body relies more on fat and begins producing more ketones. The timing varies widely; ketone levels usually rise more noticeably in longer fasts.
Cellular Recycling (Autophagy)
Fasting is thought to increase autophagy, the process cells use to break down and recycle components. Most of the detailed evidence comes from animal and cell studies; how long a fast needs to be for a meaningful effect in humans is not known. See autophagy and fasting.
Growth Hormone
Studies of longer fasts have observed increases in growth hormone secretion. The practical significance for muscle or fat loss is uncertain.
What Interrupts a Fast
In practice, the main issue is energy intake:
- Carbohydrate: raises blood glucose and insulin most directly
- Protein: also stimulates insulin and nutrient-sensing pathways
- Fat: has little effect on insulin but still provides calories
- Amount matters: there is no agreed calorie cut-off; a few calories are generally treated as negligible, while a drink with dozens or hundreds of calories is effectively a small meal
Where black coffee fits:
- Only a few calories per cup
- No meaningful carbohydrate, protein, or fat
- Not expected to cause a meaningful insulin response in most people
Black Coffee and Fasting
Black coffee, meaning coffee brewed with water and nothing added, is generally considered compatible with fasting.
Nutritional Profile of Black Coffee
Per 8 oz (240 ml) Cup of Brewed Black Coffee (approximate)
- Calories: about 2-5
- Carbohydrate: about 0 g
- Protein: under 0.5 g
- Fat: about 0 g
- Caffeine: roughly 80-100 mg on average; varies with the beans, brew strength, and cup size
This small amount of energy is generally considered negligible for intermittent fasting purposes.
How Black Coffee Relates to Fasting
Insulin
Effect: Minimal
Black coffee on its own is not expected to raise insulin meaningfully. Research on caffeine and glucose metabolism is mixed, and responses differ between people.
Autophagy
Effect: Unclear
Some animal and laboratory studies suggest coffee compounds may influence autophagy, but this has not been shown in human fasting studies. It is reasonable to say black coffee is unlikely to interfere, not that it enhances anything.
Ketosis
Effect: Not expected to interfere
Black coffee contains almost no carbohydrate. A few small studies suggest caffeine may slightly raise ketone levels, but the effect is modest.
Energy Expenditure
Effect: Small and short-lived
Caffeine can slightly and temporarily increase energy expenditure and fat use. The effect is small, tends to lessen with regular use, and is not a meaningful weight-loss strategy by itself.
Common Ways to Brew Black Coffee
Caffeine figures below are typical ranges; actual content varies widely by bean, roast, grind, brew time, and serving size.
Brewed Coffee (Drip, Pour Over)
Typical caffeine: about 70-140 mg per 8 oz
Characteristics: Clean, lighter body
Fasting compatibility: Good when drunk black
Espresso
Typical caffeine: about 60-75 mg per single shot (1 oz)
Characteristics: Concentrated, small volume
Fasting compatibility: Good when drunk straight
Americano
Typical caffeine: depends on the number of espresso shots
Characteristics: Espresso diluted with hot water
Fasting compatibility: Good; water adds volume without calories
French Press
Typical caffeine: similar to drip coffee
Characteristics: Fuller body, more coffee oils
Fasting compatibility: Good; the oils add negligible calories
Note: Unfiltered coffee (French press, boiled, Turkish) contains more cafestol, a compound that can raise LDL cholesterol when consumed regularly in larger amounts. Paper-filtered coffee contains very little.
Cold Brew
Typical caffeine: highly variable; often higher than hot coffee per serving because it is usually brewed as a concentrate
Characteristics: Smooth, often tastes less bitter
Fasting compatibility: Good when unsweetened; some people find it easier on the stomach
Caution: Check the strength; it is easy to take in more caffeine than you intended
Instant Coffee
Typical caffeine: about 30-90 mg per cup
Characteristics: Convenient, milder flavor
Fasting compatibility: Good if the label lists only coffee
Different Types of Coffee Drinks
The coffee itself is rarely the issue; what is added to it is. Here is how common drinks compare.
Generally Fasting-Compatible (Unsweetened, Nothing Added)
Usually Fine During a Fast
- Black drip or pour-over coffee
- Espresso (straight)
- Americano
- Cold brew or iced coffee (unsweetened)
- French press
- Plain instant coffee
- Decaf versions of any of the above
Coffee Drinks That Break a Fast
Lattes and Cappuccinos
Why: Mostly milk
- A typical latte or cappuccino provides roughly 100-200 calories depending on size and milk type, plus carbohydrate (lactose) and protein
Impact: This is effectively a small snack and ends the fast
Macchiato, Cortado, Flat White
Why: Smaller amounts of milk, but still meaningful
- Calories vary with size and milk; even small milk-based drinks usually contain tens of calories plus carbohydrate and protein
Flavored and Blended Coffee Drinks
Why: Sugar, syrups, milk, and toppings
- Can contain several hundred calories
- Often high in added sugar
- Best treated as a dessert or snack, not a fasting drink
Coffee with Sugar or Syrups
Why: Direct sugar intake
- A teaspoon of sugar provides about 16 calories; a tablespoon about 48
- Flavored syrups typically add around 20 calories or more per pump
- Sugar raises blood glucose and insulin
What Can You Add to Coffee?
Different additions affect a fast in different ways, and there is no official rule. The groupings below reflect common practice rather than strict scientific cut-offs.
Additions at a Glance
Generally Fine
Water
Diluting coffee with water (Americano-style) adds no calories.
Ice
Iced coffee or cold brew over ice is fine.
Cinnamon
A sprinkle adds only a calorie or two. It is often described as helping blood sugar, but evidence is mixed and this should not be relied on.
Nutmeg or Unsweetened Cocoa (a pinch)
A pinch for flavor adds very few calories and is generally considered acceptable.
Gray Area (Depends on Your Goals)
Non-Nutritive Sweeteners (Stevia, Sucralose, Aspartame, Erythritol)
Calories: zero or close to zero per serving
- For: Little or no energy; most studies find minimal direct effect on blood glucose
- Against: Research on insulin, appetite, and gut bacteria is mixed; some people find sweet tastes increase cravings
- In practice: They do not add meaningful calories. Whether to use them is a personal choice; if they make fasting easier, many people find them acceptable. Check packets and flavored products, which can contain fillers with some carbohydrate.
A Splash of Cream or Milk
1 tablespoon heavy cream: about 50 calories, mostly fat. 1 tablespoon milk: about 10 calories.
- For: Small amounts may make black coffee more palatable and help some people stick with their schedule
- Against: It does contain calories, so strictly speaking it is not a fast
- In practice: Some people accept a small splash as a compromise (sometimes called “dirty fasting”). If you do this, measure it; “a splash” tends to grow.
MCT Oil, Coconut Oil, Butter, or Ghee
1 tablespoon: roughly 100-120 calories, all fat
- For: Little carbohydrate, so insulin stays relatively low; some people find it filling
- Against: Substantial calories; a large “butter coffee” can contain several hundred calories. MCT oil can cause stomach upset or diarrhea, especially at first.
- In practice: This is not fasting in the calorie sense; it is closer to a high-fat breakfast. It may fit a low-carbohydrate eating pattern, but it can slow weight loss if it adds to rather than replaces other food.
Breaks a Fast
Milk in Larger Amounts
1/4 cup (60 ml): roughly 20-40 calories depending on fat content, with lactose and protein
Plant-Based Milks (Oat, Soy, Almond, etc.)
1/4 cup: roughly 10-40 calories depending on type and sweetening
- Oat milk: higher in carbohydrate
- Soy milk: contains protein
- Unsweetened almond milk: lowest in calories, but still not calorie-free
- “Barista” and flavored versions often contain added sugar or oil
Sugar, Honey, Agave, Syrups
These are sugars that raise blood glucose. They break a fast.
Collagen or Protein Powder
1 scoop: commonly 40-120 calories, mostly protein
Protein provides energy and stimulates insulin, so it breaks a fast even though collagen coffee is sometimes marketed for fasting.
The "Dirty Fasting" Approach
What Is Dirty Fasting?
“Dirty fasting” is an informal term for allowing a small number of calories, usually from a splash of cream or a little fat in coffee, during the fasting window to make it easier to stick with. There is no research-based definition or calorie limit.
When it might be reasonable:
- Your main goal is sustainable weight management
- It genuinely helps you stick with your eating schedule
- You keep the amount small and consistent
Trade-offs:
- It is not a fast by strict definition
- Calories can creep up without you noticing
- Any effects of fasting that depend on very low intake may be reduced; how much is unknown
Why Coffee Can Help During Fasting
For many people, the main practical value of coffee during fasting is that it makes the fasting window easier to get through. Some of coffee's broader health associations come from observational studies, which show links rather than cause and effect.
Practical Benefits
1. May Take the Edge Off Hunger
Many people find a cup of coffee helps them get through the morning, although research on coffee and appetite is mixed and the effect seems to vary between individuals.
Possible reasons:
- Caffeine is a stimulant and may temporarily reduce appetite in some people
- A warm drink provides volume and a sense of fullness
- A coffee routine can replace the habit of eating breakfast
2. Alertness and Focus
Caffeine blocks adenosine, a chemical that builds up during waking hours and promotes sleepiness. This is why coffee increases alertness, whether or not you are fasting. Some people feel sharper during a fast; others feel tired or foggy, especially in the first weeks.
3. Exercise Performance
Caffeine is one of the better-studied sports supplements. Research suggests moderate doses taken before exercise can modestly improve endurance and reduce how hard exercise feels for many people. Effects vary, and on an empty stomach caffeine can cause nausea or jitters. See fasted cardio for more on training while fasting.
4. Small Effect on Energy Use
Caffeine can slightly and briefly increase energy expenditure and the use of fat for fuel. The effect is small, tends to diminish with regular use, and should not be expected to drive weight loss on its own.
Broader Health Associations
Plant Compounds
Coffee contains polyphenols such as chlorogenic acids. Their effects in the body are still being studied.
Long-Term Health Associations
Large observational studies have linked moderate coffee intake with a lower risk of type 2 diabetes, some liver conditions, and some neurological diseases. These studies show associations, not proof that coffee causes these outcomes.
Autophagy
Some animal studies suggest coffee compounds may influence autophagy. Whether this applies to people who fast is not known.
A Reminder
Coffee is optional. Fasting does not require it, and water or tea work just as well for many people.
Potential Drawbacks and Who Should Avoid
Coffee does not suit everyone, and some side effects can feel stronger on an empty stomach.
Potential Negative Effects
1. Stomach Discomfort and Reflux
Coffee can stimulate stomach acid and gut activity, which some people find uncomfortable on an empty stomach.
More likely if you:
- Have a sensitive stomach
- Have reflux (GERD), gastritis, or ulcers
Things to try:
- Drink a glass of water first
- Reduce the amount or dilute it more
- Try cold brew or a darker roast, which some people tolerate better
- Switch to tea or decaf
- Have coffee with your first meal instead of during the fast
- If symptoms persist, talk to your doctor
2. Jitters, Anxiety, and Palpitations
Caffeine sensitivity varies widely, and effects can feel stronger without food. See also cortisol and fasting.
Warning signs of too much caffeine:
- Racing heart or palpitations
- Shakiness
- Feeling anxious or on edge
- Headache or trouble concentrating
Options:
- Cut down, or switch to half-caff or decaf
- Try green tea, which has less caffeine
- Choose caffeine-free herbal tea or water
- Seek medical advice if you have chest pain or a persistently irregular heartbeat
3. Disrupted Sleep
Caffeine stays in the body for many hours, and poor sleep can make fasting harder by increasing hunger and fatigue. See fasting and sleep.
How long caffeine lasts:
- Caffeine's half-life is often around 4-6 hours in healthy adults, but it varies widely between people
- With a 5-hour half-life, about a quarter of a 2 PM coffee's caffeine is still in your system at midnight
Sleep-friendly habits:
- Set a caffeine cut-off time, commonly 8 or more hours before bed
- Switch to decaf in the afternoon if you are sensitive
- Notice whether your sleep changes when you adjust intake
4. Dependence and Withdrawal
Regular caffeine use leads to tolerance, and stopping suddenly can cause withdrawal symptoms.
Common withdrawal symptoms:
- Headache
- Tiredness and low concentration
- Irritability
If you want to cut back:
- Reduce gradually over a week or two rather than stopping abruptly
- Mix regular and decaf to lower the dose step by step
- Headaches early in a fast are sometimes caffeine withdrawal rather than hunger, so keep your usual caffeine intake steady when you start fasting
Who Should Avoid or Limit Coffee While Fasting
Consider avoiding or limiting coffee, and talk to your healthcare provider, if you:
- Are pregnant, trying to conceive, or breastfeeding (caffeine guidance is lower; fasting is generally not advised in pregnancy)
- Have an anxiety or panic disorder
- Have heart rhythm problems or palpitations
- Have high blood pressure that is not well controlled
- Have reflux, gastritis, or ulcers
- Are very sensitive to caffeine
- Have trouble sleeping
- Take medications that interact with caffeine, or that require food (check with your doctor or pharmacist; see fasting and medications)
- Have osteoporosis or low bone density and drink a lot of coffee
- Are under 18
Timing Your Coffee
There is no single best time to drink coffee while fasting. The most important timing factor is usually your bedtime.
Right After Waking or Later?
Upon Waking vs. Delayed Coffee
Waiting a While After Waking
Cortisol naturally rises in the first hour or so after waking. Some people suggest delaying coffee by an hour or two for this reason, but there is little direct evidence that it improves energy or tolerance. It may simply spread your caffeine more evenly through the morning.
Coffee Soon After Waking
Plenty of people drink coffee soon after waking without any problems. It can be a useful ritual that marks the start of the day and helps with morning hunger.
In practice: If coffee soon after waking works for you, there is no strong reason to change. If you tend to crash or feel jittery, try a glass of water first and have coffee a little later.
Coffee Across the Fasting Window
Morning
Why: Can help with the hunger many people feel at their usual breakfast time
Tip: Drink water too; start with a glass before coffee
Late Morning
Why: Some people find a second cup useful for the last stretch before a midday meal
Tip: Keep an eye on your total caffeine for the day
Early Afternoon
Why: Can help if your eating window starts later in the day
Tip: For most people this is about the latest time before sleep may be affected
Late Afternoon and Evening
Why: Generally best avoided
Tip: Choose decaf, herbal tea, or sparkling water instead
Example Coffee Schedules
Example 1: 16:8 (Eating 12 PM - 8 PM)
- 7:30 AM: Wake up, glass of water
- 8:00-9:00 AM: First black coffee
- 10:30 AM: Second coffee or tea if wanted
- 12:00 PM: First meal
Example 2: 18:6 (Eating 2 PM - 8 PM)
- 7:00 AM: Wake up, water
- 8:00 AM: First coffee
- 11:00 AM: Second coffee, tea, or sparkling water
- 2:00 PM: First meal
Example 3: One Meal a Day (Eating Around 6 PM)
- 7:00 AM: Wake up, water
- 8:30 AM: First coffee
- 12:00 PM: Second coffee or tea around the usual lunch hour
- Afternoon: Water, herbal tea, or decaf
- 6:00 PM: Meal
Practical Tips
How Much Caffeine?
General Guidance
- Healthy adults: major food safety agencies (such as the US FDA and the European Food Safety Authority) consider up to about 400 mg of caffeine a day generally safe for most healthy adults
- Pregnancy: guidance is usually 200 mg a day or less
- Individual variation: some people feel unwell on much less; there is no need to reach any limit
Typical Caffeine Content (approximate)
- Brewed coffee (8 oz): about 70-140 mg
- Espresso (single shot): about 60-75 mg
- Cold brew: highly variable, often higher per serving
- Instant coffee (8 oz): about 30-90 mg
- Black tea (8 oz): about 40-70 mg
- Green tea (8 oz): about 25-50 mg
Example: Two large mugs of strong coffee plus a double espresso can approach or exceed 400 mg. Coffee-shop sizes are often much larger than 8 oz.
Brewing Tips
Make It Easy to Drink Black
- Freshly ground beans often taste less bitter
- Avoid over-extracting or keeping coffee on a hot plate
- Try different roasts or cold brew if you dislike black coffee
Filtered vs Unfiltered
- Paper filters remove most cafestol
- If you have high LDL cholesterol and drink several cups a day, filtered coffee may be the better choice
Hydration
Coffee and Fluid Intake
Caffeine has a mild diuretic effect, but moderate coffee intake still contributes to your daily fluid intake in regular drinkers. During fasting, it is still sensible to drink plenty of water:
- Start with water: have a glass before your first coffee
- Keep water handy: sip regularly through the fasting window
- Longer fasts: electrolytes (especially sodium) may matter more; see electrolytes and fasting
- Watch for: headache, dark urine, or dizziness, and drink more water or end the fast if you feel unwell
Managing Tolerance
Keeping Caffeine Under Control
- Set a daily limit: for example, two cups
- Set a cut-off time: based on your bedtime
- Cut back gradually: if you want to reduce, taper over a week or two
- Use decaf: for extra cups when you want the ritual without the caffeine
Alternative Beverages During Fasting
If coffee doesn't suit you, or you want variety, these unsweetened drinks are generally considered fasting-compatible.
Tea Options
Green Tea
Caffeine: about 25-50 mg per 8 oz
- Less caffeine than coffee
- Contains L-theanine, which some people find makes caffeine feel smoother
- Rich in polyphenols (catechins)
Good for: People who want a gentler caffeine lift
Black Tea
Caffeine: about 40-70 mg per 8 oz
- Moderate caffeine
- Contains its own polyphenols (theaflavins)
- Drink it without milk or sugar during the fast
Good for: A coffee alternative with moderate caffeine
Oolong Tea
Caffeine: about 30-50 mg per 8 oz
- Flavor sits between green and black tea
- Moderate caffeine
Good for: Variety
Herbal Teas (Caffeine-Free)
Caffeine: none
- Peppermint: refreshing; some people find it settles the stomach (it can worsen reflux in others)
- Ginger: warming; often used for nausea
- Chamomile: a calming evening option
- Rooibos: naturally slightly sweet taste
Good for: Evenings and caffeine-sensitive people. Choose plain teas without added fruit pieces or sweeteners. Some herbal products are not advised in pregnancy or with certain medications.
Coffee Alternatives
Decaf Coffee
Caffeine: usually a few mg per cup
- Keeps the taste and ritual of coffee
- Useful for afternoons without affecting sleep
Chicory "Coffee"
Caffeine: none (if pure chicory)
- Coffee-like flavor from roasted chicory root
- Contains inulin, a type of fiber, so it provides a small amount of energy
- Can cause gas or bloating in some people
Mushroom Coffee Blends
Caffeine: varies; many contain regular coffee
- Plain blends are low in calories
- Health claims made for added mushroom extracts are not well supported
- Check the label for added sugar or creamer
Other Fasting-Friendly Drinks
Additional Options
- Plain water: the simplest choice
- Sparkling water: adds variety; choose unsweetened
- Water with a squeeze of lemon: a few calories at most
- Diluted apple cider vinegar: optional; see apple cider vinegar and fasting
- Bone broth: contains some calories and protein; some people use it during longer fasts, but it is not strictly fasting (see bone broth fasting)
Common Questions Answered
Can I drink coffee during longer fasts (24+ hours)?
Answer: Black coffee is commonly used during longer fasts, but a few extra cautions apply:
- Stomach upset and jitters may be more noticeable
- Keep caffeine moderate and drink plenty of water
- Pay attention to electrolytes
- If you feel dizzy, faint, or unwell, stop the fast
Longer fasts are not suitable for everyone; talk to your healthcare provider first if you have a medical condition or take medication.
Will coffee stop autophagy?
Answer: There is no good evidence that black coffee stops autophagy. It contains almost no calories or protein. Claims that coffee boosts autophagy come mainly from animal and laboratory studies and have not been confirmed in people.
Adding protein (such as collagen) or substantial calories (butter, MCT oil) means you are no longer fasting in the usual sense.
Can I have coffee before a morning workout while fasting?
Answer: Many people do. Caffeine may modestly help endurance and make exercise feel easier.
Timing: about 30-60 minutes before training is common
Caution: On an empty stomach, caffeine plus hard exercise can cause nausea or light-headedness in some people. Start with easier sessions and keep water nearby.
Does the type of coffee bean matter?
Answer: Not for fasting purposes. All plain black coffee is similar in calories.
- Arabica vs. Robusta: Robusta generally has more caffeine
- Light vs. dark roast: differences in caffeine are small and depend on how the coffee is measured
- Origin and blends: personal preference
Can I drink iced coffee or cold brew while fasting?
Answer: Yes, as long as nothing is added.
- Cold brew often tastes smoother, which makes it easier to drink black
- It can be strong in caffeine, so check the serving size
- Bottled or canned versions may contain sugar or milk; read the label
What if coffee makes me hungrier?
Answer: Some people notice this. Stomach discomfort or jitters can feel like hunger, and responses vary.
- Drink a glass of water first
- Have coffee later in the fasting window instead of first thing
- Try decaf to see whether caffeine is the trigger
- Switch to tea
- Skip coffee during the fast if it consistently makes things harder
Is instant coffee okay for fasting?
Answer: Yes, plain instant coffee is fine.
- Check the ingredients list says only coffee
- It usually has a bit less caffeine than brewed coffee
- Avoid “3-in-1” mixes, which contain sugar and creamer
The Bottom Line
Plain black coffee is generally considered compatible with intermittent fasting because it contains only a few calories. For many people it makes the fasting window easier by providing a routine and taking the edge off hunger, though it is entirely optional.
Milk, sugar, syrups, protein powders, and larger amounts of cream, butter, or oil add calories and mean you are no longer strictly fasting. A small splash of milk or cream is a personal trade-off that some people choose for sustainability.
Watch your total caffeine, avoid it late in the day, and switch to decaf, tea, or water if coffee causes stomach upset, anxiety, or poor sleep. If you are pregnant, have a heart condition, or take medication, check with your healthcare provider.
Key Takeaways
- Black coffee generally does not break a fast
- Coffee with milk, sugar, syrups, or protein does
- Small amounts of cream or fat are a gray area; larger amounts are effectively a meal
- Coffee may help with hunger and alertness, but effects vary
- Possible downsides include stomach upset, jitters, and poor sleep
- Most healthy adults are advised to stay at or below about 400 mg of caffeine a day (lower in pregnancy)
- Set a caffeine cut-off time well before bed
- Tea, decaf, and water are good alternatives