Question to Luise from the Hello Inside science department about Anna's interview: How can Anna Journey be explained scientifically? Does it make sense? Is there a scientifically proven connection between blood sugar and sleep and cognitive performance?
Luise: Anna's journey impressively demonstrates how lifestyle changes can have a significant impact on well-being – and science backs her up. The connection between blood sugar regulation, sleep, and cognitive performance is indeed well documented.
Insulin and sleep: Does blood sugar level affect sleep quality?
Insulin plays a central role in metabolism and influences how stable blood sugar is throughout the day. If blood sugar levels fluctuate significantly in the evening, this can lead to sleep disturbances. Studies, including those by Dr. Satchin Panda and Dr. Eve Van Cauter, show that people with unstable blood sugar levels often have sleep problems and are more prone to hormonal imbalances, including those affecting the stress hormone cortisol.
Through the Hello Inside program, Anna discovered for the first time the connection between her blood sugar levels and her sleep quality: "On days with strong blood sugar fluctuations, I sleep significantly worse."
And the effect goes beyond insulin: Hormonal interactions: insulin, cortisol and melatonin
The regulation of insulin and blood sugar is closely linked to other hormones that influence sleep. When blood sugar levels are elevated due to excessive sugar consumption or stress, the body produces more insulin, which in turn affects cortisol levels. This, in turn, can inhibit the nighttime production of melatonin, making it harder to fall asleep.
Anna noticed that her body reacted to stressful days and unbalanced meals with sleep disturbances. Thanks to her tracking data, we at COaching quickly saw the connection and understood how Anna could keep her insulin levels stable with an adjusted routine.
Question: How does blood sugar affect sleep?
Unstable blood sugar levels, especially those with large fluctuations between peaks and falls, negatively impact the body in several ways. When blood sugar levels rise rapidly after a high-carbohydrate or sugary meal, insulin is released to transport the sugar from the blood into the cells. This rapid rise can lead to an equally rapid drop in blood sugar—which the body often perceives as an "emergency." In this situation, the body releases stress hormones such as cortisol and adrenaline to quickly raise blood sugar again. The problem is that cortisol and adrenaline have an activating effect and can disrupt sleep because they put the body into a kind of "alarm state."
Dr. Eve Van Cauter , a leading researcher in the field of sleep and metabolism at the University of Chicago, has shown in her studies that poor sleep and insulin resistance often go hand in hand. Her research shows that lack of sleep can reduce insulin sensitivity, meaning the body has a harder time responding to insulin and is less able to utilize glucose. This vicious cycle means that people who sleep poorly often experience greater fluctuations in blood sugar—and vice versa. This altered insulin resistance also increases the risk of fatigue and difficulty concentrating.
Question: What is the connection with cognitive performance?
Blood sugar levels directly affect the brain. Our brain needs a constant supply of energy in the form of glucose to function optimally. Fluctuating blood sugar levels, like the ones Anna experienced initially, can lead to a lack of energy in the brain, which can manifest as difficulty concentrating, mental fatigue, and even irritability. Dr. Satchin Panda , known for his research on chronobiology, emphasizes that keeping blood sugar levels stable is not only important for physical health, but also for mental health to avoid fatigue and cognitive decline. His approach of aligning eating habits with natural day-night cycles has shown in several studies that regular meal times help stabilize blood sugar and support mental performance.
Question: Why does regular monitoring and coaching help?
Anna's approach of checking her blood sugar levels once a quarter is actually a very good strategy for staying healthy long-term . Monitoring with a continuous glucose monitor (CGM) not only provides a snapshot in time, but also helps identify individual patterns and adapt lifestyle changes. This type of self-monitoring supports awareness and can help maintain healthy habits and prevent relapses in the long term.
The coaching Anna receives in the Hello Inside program is also an important aspect : It not only provides guidance and support , but also helps her set specific goals and reflect on what's working well and where there's room for improvement . A similar approach is used in behavioral research , with studies showing that supported self-monitoring and structured feedback significantly increase the chances of long-term behavior change.
