Does coffee without food spike cortisol?

December 31, 2025 •

4 min read

According to some wellness influencers and health practitioners, drinking coffee first thing in the morning on an empty stomach can contribute to elevated cortisol levels and other issues like anxiety, gut problems, and energy crashes. This has sparked a widespread discussion about whether your daily routine could be impacting your body's hormonal balance and stress response.

Quick Summary

Drinking coffee on an empty stomach can temporarily increase cortisol, a stress hormone, but the effect varies by individual sensitivity. Eating food can buffer this response.

Key Points

Spike is temporary: Caffeine can cause a temporary increase in cortisol, but this isn't necessarily harmful for most people.
Empty stomach amplifies: For sensitive individuals, drinking coffee on an empty stomach can lead to a more pronounced and potentially uncomfortable cortisol spike due to faster caffeine absorption.
Timing is key: Consuming coffee when cortisol is already naturally high (first thing in the morning) may compound the effect; waiting an hour or two can help regulate this.
Food acts as a buffer: Eating a meal with protein and fiber helps to slow caffeine absorption, moderate the cortisol response, and protect the stomach lining.
Individual sensitivity varies: Some people are more prone to jitters, anxiety, and digestive issues from coffee, and their personal response is the most reliable indicator of how to proceed.
Listen to your body: The best approach is to pay attention to your body's specific reactions and adjust your coffee habits accordingly to find what works for you.

Understanding Cortisol and Caffeine

Cortisol, often called the "stress hormone," is a steroid hormone produced by your adrenal glands. It plays a crucial role in regulating your body's stress response, metabolism, blood pressure, and blood sugar levels. Your cortisol naturally follows a circadian rhythm, with levels peaking within 30 to 45 minutes of waking up to help you become more alert.

Caffeine is a central nervous system stimulant that can independently trigger a temporary increase in cortisol production. For most people, this temporary boost is part of coffee's desirable energizing effect. However, the intensity and significance of this effect are highly individual and depend on several factors, including your tolerance level and overall stress load.

The Empty Stomach Effect on Cortisol and Digestion

Combining a natural cortisol spike with a caffeine-induced one, especially without any food, is where the concern arises for sensitive individuals. When you drink coffee on an empty stomach, the caffeine is absorbed faster, potentially leading to a more pronounced hormonal and nervous system response.

Potential Consequences of a Heightened Response

Exaggerated Jitters and Anxiety: A large, rapid rise in cortisol can push your nervous system into overdrive, leading to feelings of nervousness, anxiety, or irritability.
Energy Crashes: While caffeine provides a short-term boost, the amplified cortisol response can sometimes be followed by a more significant crash later, as your body attempts to rebalance itself.
Blood Sugar Fluctuation: For some individuals, caffeine can cause a temporary spike in blood sugar levels. Without food to help stabilize these levels, a subsequent drop can lead to fatigue and cravings.
Increased Gastric Acidity: Coffee is acidic and stimulates the production of stomach acid. Without food to absorb this acid, it can irritate the stomach lining, potentially causing acid reflux, heartburn, or general discomfort. This is a particular concern for people with existing gut sensitivities like IBS.

Optimizing Your Morning Coffee Routine

To mitigate potential negative effects, especially if you are sensitive to caffeine or prone to anxiety, consider adjusting your routine. Waiting to drink your coffee or pairing it with food can make a significant difference.

Strategies to Prevent a Cortisol Spike

Time it Right: Wait at least 60 to 90 minutes after waking up to have your coffee. This allows your natural cortisol levels to begin declining before adding caffeine to the mix.
Pair with Protein and Fiber: Eating a balanced breakfast with protein, healthy fats, and fiber can help buffer the effects of caffeine and stabilize blood sugar. This gives the stomach acid something to digest and slows the absorption of caffeine.
Choose Alternatives: If you find that coffee, even with food, affects you negatively, consider alternatives like lower-caffeine sources (matcha or green tea) or decaf coffee. Note that decaf still contains trace amounts of caffeine and other compounds that can have a milder effect.
Stay Hydrated: Start your day with a large glass of water to rehydrate your body after sleep. This can be a gentle way to boost energy before relying on caffeine.
Practice Mindfulness: Stress management techniques like deep breathing or a short walk in the morning can also help regulate cortisol levels naturally.

Comparing Coffee with and without Food


Feature	Coffee on an Empty Stomach	Coffee with Food (Protein, Fiber)
Cortisol Response	Potentially more dramatic and acute spike, especially for sensitive individuals.	More gradual and stable rise, buffered by nutrient absorption.
Digestive Impact	Increased acidity, potential for irritation, acid reflux, and discomfort.	Food absorbs stomach acid, reducing the risk of digestive upset.
Energy & Focus	Quick, intense initial jolt possibly followed by a noticeable crash.	More sustained, balanced energy and improved focus throughout the morning.
Nutrient Absorption	Can interfere with the absorption of minerals like iron, especially if consumed with an iron-rich meal.	Minimal impact on iron absorption if coffee is consumed an hour or more after the meal.
Anxiety & Jitters	Higher risk of feeling jittery, nervous, or experiencing a caffeine-induced anxiety attack.	Less likely to produce pronounced anxiety or jitters.

Conclusion

While a single cup of coffee on an empty stomach won't cause long-term damage for most healthy individuals, the accumulated effect of daily, morning-time consumption can create or exacerbate issues for those who are sensitive. The decision of whether to drink coffee with or without food ultimately comes down to individual biochemistry and how your body responds. By being mindful of your body's signals—such as increased anxiety, digestive upset, or energy crashes—you can fine-tune your coffee routine. For those experiencing these negative side effects, delaying your coffee intake, pairing it with a nutrient-rich breakfast, or exploring milder alternatives is a simple but effective strategy to enjoy your brew without the hormonal roller coaster. For additional reading on caffeine's effect on cortisol reactivity, see this study in Psychosomatic medicine.

Frequently Asked Questions

Yes, many people can drink black coffee on an empty stomach without issues. However, if you are sensitive to caffeine or prone to digestive upset, it may cause a more significant cortisol spike and increase stomach acid, leading to discomfort.

Decaf coffee contains minimal caffeine but can still cause a mild increase in cortisol, although it is less pronounced than with regular coffee. This is due to other compounds and the body's sensory response to the drink.

Some health experts recommend waiting 60 to 90 minutes after waking up. This allows your natural morning cortisol peak to subside before introducing caffeine, potentially resulting in a smoother energy lift.

Pair your coffee with a balanced breakfast containing protein and fiber, such as eggs with avocado, a protein smoothie, or oatmeal with nuts. This will help slow caffeine absorption and buffer the hormonal response.

For those sensitive to caffeine, drinking coffee on an empty stomach can trigger or worsen feelings of nervousness and anxiety, as the resulting cortisol spike can push the nervous system into overdrive.

Yes, coffee stimulates gastric acid production. Without food to buffer it, this can irritate the stomach lining and cause or worsen issues like acid reflux, heartburn, and gastritis, especially in sensitive individuals.

No, it doesn't completely prevent a cortisol spike, but it can significantly moderate and stabilize the response. The food slows down caffeine absorption, leading to a gentler and more sustained effect.