Why am I in ketosis at night but not in the morning?

October 15, 2025 •

4 min read

According to studies, ketone levels can fluctuate significantly throughout a 24-hour cycle, often peaking overnight and dropping in the early morning. This phenomenon can be confusing for those on a ketogenic diet who wonder, "Why am I in ketosis at night but not in the morning?" It’s a common experience rooted in normal physiological processes.

Quick Summary

This article explores the physiological reasons behind lower morning ketone levels, including the role of the dawn phenomenon and hormonal fluctuations. It outlines dietary, lifestyle, and other factors that influence daily ketone readings, offering strategies to support consistent ketosis.

Key Points

The Dawn Phenomenon: Early morning hormonal surges of cortisol and growth hormone cause the liver to release glucose, temporarily lowering ketone levels.
Normal Metabolic Fluctuation: It is normal for ketone levels to fluctuate throughout the day, often peaking at night after a prolonged fast and dipping in the morning.
Other Influencing Factors: Diet composition, protein intake, physical activity, and stress can all contribute to varying ketone readings.
Keto-Adaptation: As the body becomes more efficient at using ketones for fuel, it may produce fewer excess ketones, leading to more stable but not necessarily higher readings.
Testing Timing: For a more accurate baseline, some experts recommend waiting an hour or two after waking to measure ketones, as the initial reading can be skewed by the dawn phenomenon.
Strategic Adjustments: To help stabilize readings, consider having an earlier dinner, optimizing hydration and electrolytes, and potentially using MCT oil.
Holistic Approach: Focus on consistent dietary adherence and overall metabolic health, rather than becoming overly concerned with minor daily fluctuations.

Understanding the Dawn Phenomenon

The primary reason many people experience lower ketone levels in the morning is a natural biological process known as the dawn phenomenon. This process is your body’s way of preparing to wake up and start the day. Even after a night of fasting, your liver releases a surge of glucose to provide energy for the day ahead.

The Hormonal Cascade

Between approximately 3 a.m. and 8 a.m., your body releases counter-regulatory hormones such as cortisol and growth hormone. These hormones trigger your liver to produce and release glucose, causing a temporary rise in your blood sugar. This natural rise in glucose leads to an insulin response, which in turn suppresses ketone production. This hormonal cascade is the main reason your ketone readings might appear lower upon waking, despite being in ketosis the night before.

Other Contributing Factors to Fluctuating Ketone Levels

While the dawn phenomenon is the most significant contributor, several other elements can influence your daily ketone measurements. Understanding these factors can help you better manage your ketogenic lifestyle.

1. Diet Composition and Timing

Your dinner choices can significantly impact your morning readings. A late-night meal, particularly one that is higher in protein, can affect overnight ketosis. The body can convert excess protein into glucose through a process called gluconeogenesis, which can reduce ketone production. Eating your last meal earlier in the evening may help maintain more stable overnight readings.

2. Physical Activity

Exercise can also cause fluctuations in ketone levels. Intense exercise can lead to a temporary drop in blood ketones as your body utilizes glucose for immediate fuel. Conversely, prolonged endurance exercise can increase ketone production as you burn through glycogen stores. The timing of your workouts relative to when you test your ketones will affect your readings.

3. State of Keto-Adaptation

Those new to the keto diet often see higher and more volatile ketone readings. As your body becomes more fat-adapted—more efficient at using fat for fuel—it may produce fewer excess ketones, leading to a more stable but not necessarily higher reading. A low morning reading might not indicate you’ve been kicked out of ketosis, but rather that your body has become more efficient.

4. Stress and Sleep

Chronic stress can lead to persistently elevated cortisol levels, which can interfere with ketosis. Similarly, sleep deprivation can also disrupt your body's metabolic rhythms. Ensuring adequate, quality sleep can help your body's hormones and metabolism stay in balance.

5. Hydration and Electrolytes

Dehydration can cause lower ketone readings, especially with urine strips. When you are dehydrated, your urine becomes more concentrated, and your body flushes out electrolytes and water. Maintaining proper hydration by drinking plenty of water and ensuring adequate electrolyte intake is crucial.

How to Address the Morning Ketone Drop

Here are some strategies to help stabilize your morning ketone readings:

Evening Meals: Ensure your evening meal is low in carbohydrates and moderate in protein. Focus on healthy fats to fuel your overnight ketosis.
Intermittent Fasting: Extending your overnight fast can encourage your body to stay in a fat-burning state for longer, potentially offsetting the dawn phenomenon.
Monitor and Adjust: Consider your individual factors, such as activity level and diet, when interpreting your ketone readings. A slightly lower morning reading is normal and not a sign of failure.
MCT Oil: Some people use MCT (medium-chain triglyceride) oil to provide a quick source of ketones that can help increase morning readings.
Manage Stress: Incorporate stress-reducing techniques like meditation, deep breathing, or light exercise to help regulate cortisol levels.
Quality Sleep: Prioritize getting 7-9 hours of quality sleep per night to support overall metabolic health.

Comparison Table: Morning vs. Nighttime Ketone Levels


Factor	Nighttime Ketone Levels	Morning Ketone Levels
Metabolic State	Body has used up stored glycogen from the day's activity and is actively producing ketones from fat storage.	Liver releases stored glucose to prepare for the day, which can temporarily reduce ketone production.
Hormonal Influence	Cortisol and growth hormone are typically lower, allowing for steady ketosis.	Cortisol and growth hormone surge in the early morning (dawn phenomenon), prompting glucose release and suppressing ketones.
Fasting Duration	Represents the end of an overnight fast, where the body has been consistently burning fat.	Represents the end of the fasting period, but hormonal changes trigger a shift toward glucose utilization.
Efficiency	Ketone production is the body's main energy source during rest and prolonged fasting.	The body momentarily prioritizes a small amount of glucose for waking energy, causing a temporary dip in ketones.
Testing Window	Measured several hours after your last meal, reflecting the peak of fat-burning.	Measured immediately upon waking, during the peak of hormonal-induced glucose release. Best to wait an hour or two to re-test.

Conclusion

The fluctuation of ketone levels, where readings are lower in the morning compared to the evening, is a normal physiological occurrence. The dawn phenomenon, driven by hormonal shifts, is the primary reason for this dip. It's not a sign that your diet is failing or that you've been knocked out of ketosis. Instead, it’s a natural metabolic adjustment. By focusing on your overall dietary patterns, managing stress and sleep, and understanding the nuances of your body’s rhythms, you can confidently navigate your keto journey without being discouraged by a low morning reading. Consistent low-carb, moderate-protein eating, combined with mindful lifestyle habits, is the key to maintaining metabolic flexibility and achieving long-term success.

Frequently Asked Questions

The dawn phenomenon is a natural early-morning rise in blood sugar caused by a surge of hormones like cortisol and growth hormone, which signal the liver to produce more glucose. This can temporarily suppress ketone production, leading to lower morning readings.

Not necessarily. A low morning reading is often a result of the dawn phenomenon and is normal, especially for people who are fat-adapted. If your evening readings are good and you are adhering to your keto macros, you are likely still in ketosis, and your body is simply adjusting.

Yes. Many recommend waiting an hour or two after waking up to get a more accurate baseline reading of your ketones. The initial reading immediately upon waking is most likely to be affected by the hormonal changes of the dawn phenomenon.

Yes. Excessive protein intake, particularly during your last meal, can lead to gluconeogenesis, a process where your body converts protein into glucose. This can raise your blood sugar and lower your ketone levels, potentially affecting your morning readings.

Yes, chronic stress and inadequate sleep can interfere with ketosis. Stress hormones like cortisol can increase blood sugar levels, and disrupted circadian rhythms can affect your metabolism. Prioritizing quality sleep and stress management is beneficial for maintaining metabolic balance.

To increase morning ketone levels, consider eating an earlier, lower-protein dinner, extending your overnight fast, or adding MCT oil to your morning routine. Consistent hydration and managing stress can also help support stable readings.

Urine ketone strips measure excess ketones being excreted from the body, not blood ketone levels. Their accuracy can be affected by hydration levels; therefore, they are not the most reliable for detailed daily monitoring. Blood ketone meters provide the most accurate real-time measurement.