Does Skipping Meals Raise Cortisol? The Surprising Connection

November 18, 2025 •

4 min read

Research indicates that skipping meals is linked to elevated cortisol levels, triggering a stress response in the body. Forgoing food, particularly after an overnight fast, causes a drop in blood sugar, prompting the adrenal glands to release the stress hormone cortisol to raise glucose levels.

Quick Summary

Skipping meals triggers a drop in blood sugar, forcing the body to release the stress hormone cortisol to compensate. This hormonal response can disrupt natural circadian rhythms, negatively affecting metabolic health, mood, and sleep patterns.

Key Points

Cortisol Spike: Skipping meals causes a drop in blood sugar, prompting the body to release cortisol to increase glucose levels.
Stress Response: The body interprets a lack of food as stress, activating a 'fight or flight' response via elevated cortisol.
Meal Timing Matters: Skipping breakfast can lead to a midday cortisol spike, while skipping dinner might lower evening levels, with different effects on circadian rhythms.
Gender Differences: Some research suggests women's bodies may be more sensitive to fasting-induced cortisol increases, potentially disrupting hormone balance and menstrual cycles.
Metabolic Consequences: Chronic elevation of cortisol from skipping meals can contribute to weight gain, particularly abdominal fat storage, and increase insulin resistance.
Affects Mood and Sleep: Higher cortisol levels, especially if dysregulated, can cause anxiety, mood swings, and disrupt the sleep cycle.
Management Strategies: Eating regular, balanced meals, managing stress, getting adequate sleep, and avoiding caffeine on an empty stomach can help regulate cortisol.

The Physiological Connection Between Fasting and Stress

Cortisol is often referred to as the body's primary stress hormone, playing a vital role in the 'fight or flight' response. It is responsible for regulating various physiological processes, including metabolism, blood sugar levels, and inflammation. The body has a natural circadian rhythm for cortisol, with levels typically peaking in the morning to help you wake up and gradually declining throughout the day.

When you go for an extended period without eating, such as when you skip a meal, your blood glucose levels begin to fall. The body perceives this as a state of stress or potential starvation. In response, the adrenal glands increase cortisol production to signal the liver to release stored glucose (glycogen) into the bloodstream to raise blood sugar levels. This is an adaptive survival mechanism. However, when it happens frequently due to missed meals, it can lead to chronically high or dysregulated cortisol patterns.

The Cortisol Response to Skipping Meals

Breakfast: Skipping breakfast is a particularly common trigger for this cortisol spike. After the overnight fast, blood sugar is already at its lowest. Failing to eat in the morning exacerbates this, causing a more pronounced rise in cortisol. This can lead to feeling jittery, anxious, and irritable, a state often referred to as 'hangry'.
Other Meals: While breakfast skipping is well-documented, a similar stress response can occur with any skipped meal. Low blood sugar at any point in the day can prompt the body to release cortisol to restore balance, disrupting normal hormonal rhythms.

The Impact of Chronic High Cortisol from Meal Skipping

Sustained or frequent elevation of cortisol can have several negative health consequences:

Weight Gain: Chronic high cortisol is associated with increased appetite and cravings for high-sugar and high-fat foods. It also promotes the storage of fat, particularly in the abdominal region, which is a risk factor for various metabolic diseases.
Mood and Mental Health: The feeling of being 'on edge' due to elevated stress hormones can manifest as mood swings, increased anxiety, and even depression over time.
Sleep Disruption: Cortisol's natural cycle is to decrease towards the evening to prepare for sleep. Elevated evening cortisol due to delayed or skipped meals can interfere with your sleep cycle, leading to difficulty falling or staying asleep.
Hormonal Imbalance: The hormonal cascade initiated by skipping meals can affect other critical hormones, including insulin and reproductive hormones, potentially leading to insulin resistance and irregularities in the menstrual cycle for women.

Does Intermittent Fasting Raise Cortisol?

Intermittent fasting (IF) involves regularly cycling between periods of eating and fasting. For some, this practice is manageable, but for others, especially those with pre-existing stress or hormonal issues, it can be a significant stressor. Prolonged fasting, particularly for women, can trigger a noticeable increase in cortisol. This is because the body interprets the extended period without food as a stressor, leading to a compensatory hormonal response. While short-term, acute stress can be beneficial (a process known as hormesis), chronic elevation of cortisol can negate the potential benefits of IF.

The Cortisol Impact: Skipping Breakfast vs. Skipping Dinner

Understanding the chronobiology of food intake reveals differences in how the body reacts to skipped meals at different times of day.


Factor	Skipping Breakfast	Skipping Dinner
Morning Cortisol	Elevated cortisol after the overnight fast is not adequately dampened by food, perpetuating the stress response.	Potentially slightly raised in the morning, but less pronounced than after skipping breakfast.
Midday Cortisol	Often leads to an intensified midday cortisol spike as the body struggles to provide energy.	Normal circadian fluctuations are more likely to be maintained.
Evening Cortisol	Disrupted circadian rhythm can cause cortisol levels to remain higher than normal into the evening, affecting sleep.	Studies suggest lower evening cortisol, potentially aiding sleep quality.
HPA Axis Rhythm	Can lead to a 'blunted' or flattened diurnal cortisol pattern, indicating a dysfunctional HPA axis.	May increase the amplitude of the cortisol rhythm, with higher morning and lower evening levels.
Impact on Metabolism	Can lead to higher blood sugar responses to later meals due to insulin sensitivity issues.	Better glycemic control has been observed with early time-restricted eating, which involves skipping dinner.

Strategies to Manage Cortisol and Meal Timing

Prioritize Regular Meals: Establish a consistent meal schedule to prevent blood sugar crashes that trigger cortisol release. Eating at regular intervals signals to your body that it is not in a state of starvation.
Eat a Balanced Breakfast: Consuming a breakfast with a balance of protein, healthy fats, and fiber is crucial. This provides sustained energy, stabilizes blood sugar, and prevents the morning cortisol spike.
Manage Overall Stress: The hormonal response to skipping meals can be exacerbated by other life stressors. Incorporate stress-management techniques such as meditation, yoga, or deep breathing to help lower overall cortisol levels.
Optimize Sleep: Aim for 7-9 hours of quality sleep per night. Poor sleep itself is a stressor that raises cortisol, creating a negative feedback loop with poor eating habits.
Avoid Caffeine on an Empty Stomach: Caffeine can stimulate the adrenal glands to produce more cortisol. Combining it with an empty stomach after an overnight fast can significantly increase cortisol levels, intensifying the stress response.
Mindful Exercise: Regular physical activity can help manage cortisol. However, over-exercising or intense exercise on an empty stomach can add to the stress load on the body.

Conclusion

Yes, skipping meals can indeed raise your cortisol levels, particularly when the body perceives low blood sugar as a threat. While short-term fasting can have specific physiological effects, the chronic habit of skipping meals, especially breakfast, can disrupt the body's natural circadian cortisol pattern, leading to a host of issues from weight gain and mood swings to disrupted sleep. The body thrives on consistency and proper nourishment. By prioritizing regular, balanced meals and adopting other stress-management techniques, you can effectively regulate your cortisol levels and support your overall metabolic and mental health.

NIH: Effect of a 72-h fast on plasma levels of pituitary, adrenal, thyroid...

Frequently Asked Questions

Skipping meals causes your blood sugar to drop. Your body perceives this as a stressful event and releases cortisol to signal the liver to produce more glucose to raise your blood sugar back to a normal range, which provides energy.

Skipping breakfast, especially after an overnight fast, can lead to a more pronounced spike in midday cortisol levels. In contrast, studies on early time-restricted eating (which often involves skipping dinner) suggest it can result in lower evening cortisol levels.

Yes, intermittent fasting can raise cortisol, especially with longer fasting windows. Prolonged fasting is perceived as a stressor by the body. This effect may be more pronounced in women than in men and can lead to hormonal imbalances.

Symptoms can include increased anxiety, irritability, mood swings, sleep disruption, weight gain (especially around the abdomen), cravings for unhealthy food, and a general feeling of stress or fatigue.

To lower cortisol, focus on eating regular, balanced meals that include protein, fiber, and healthy fats. Additionally, practice stress management techniques like meditation or yoga, ensure you get enough sleep, and avoid caffeine on an empty stomach.

Yes, eating balanced meals at regular intervals helps maintain stable blood sugar levels. This consistency prevents the dips in glucose that trigger the body's stress response and subsequent cortisol release.

Yes, combining caffeine with an already low blood sugar state from fasting can stimulate the adrenal glands and cause a more significant spike in cortisol than either would on its own. It's often recommended to eat before or with your morning coffee.