World Diabetes Day 2025: Does screen time before bed affect your blood sugar levels? An endocrinologist explains

Many people now have a nightly habit of scrolling through social media or watching shows before bed. We've all experienced that moment when we start to fall asleep but end up getting lost in our devices, thinking just one more episode or post won't hurt. While this may seem harmless, it can actually affect our health, particularly our blood sugar levels. Bedtime screen time can seriously affect your health. It’s not just about not getting enough sleep; it can also mess with how our bodies manage blood sugar levels. Why using screens before bed can harm you and what you can do to improve the situation?

What is the role of blue light?

Blue light is the bright light emitted by devices such as smartphones, tablets, and computers. This light can disrupt our sleep. The primary issue is that it reduces melatonin production. “Melatonin is a hormone that helps control our sleep cycle. When you use devices that emit blue light before bed, it confuses your brain into thinking it’s still day,” Dr Shehla Shaikh, Consultant Endocrinologist at Saifee Hospital, Mumbai, tells Health Shots. This stops melatonin from rising, which is what signals that it’s time to relax and prepare for sleep.

When your body doesn’t make enough melatonin, your sleep quality drops. Poor sleep leaves you feeling tired and affects how your body handles insulin. Research published in the National Institute of Diabetes and Digestive and Kidney Diseases suggests that insufficient sleep can lead to increased blood sugar levels, making it more challenging for the body to regulate glucose levels. So, if you find yourself scrolling on your phone late at night, your blood sugar might be suffering.

Does sleep affect your blood sugar levels?

Research published in The Lancet Regional Health – Europe shows a concerning fact: exposure to light at night can increase the risk of type 2 diabetes, regardless of the amount of sleep one gets. This happens because light at night disrupts our body's internal clock, keeping us in an alert state instead of allowing us to rest. When our nervous system stays too active at night, it raises stress hormones, which can lead to higher blood sugar levels.

Chronic lack of sleep, often caused by excessive screen time at night, can lead to a decreased sensitivity to insulin over time. “This insulin resistance can lead to serious health issues like obesity, diabetes, and polycystic ovarian syndrome (PCOS)”, says the doctor. For women, this may result in problems with fertility and hormone levels. Men may face a drop in testosterone and issues like erectile dysfunction due to poor sleep habits.

What problems does a sedentary lifestyle cause?

While screen time is important, we should also consider the impact of a sedentary lifestyle on our health. In our tech-focused world, we often spend long periods sitting. “This lack of activity can lead to insulin resistance and increase the risk of heart disease”, says the expert. Sitting for too long can lead to weight gain, stiff muscles, and adverse effects on blood sugar control.

To counteract the effects of prolonged screen time, it's essential to incorporate more physical activity into your daily routine. Try to stand up and take a short walk every hour. Performing simple stretches can also give your body a break and help mitigate the adverse effects of excessive screen time.

How to fix poor sleep hygiene?

Now that we understand how screen time affects blood sugar levels, how can we maintain our health while enjoying the digital world? Endocrinologist shares some strategies:

1. Limit screen time before bed: Reduce your screen time by one to two hours before bed. Use this time to read a book, meditate, or relax without using screens.
2. Use blue light filters: Many devices have a night mode that reduces blue light. Use these settings in the evening to help protect your melatonin levels.
3. Establish a relaxing pre-sleep ritual: Create a calming atmosphere by dimming the lights and avoiding any stimulating activities. This can include taking a warm bath, journaling, or practising deep breathing exercises.
4. Stick to a consistent sleep schedule: Going to bed and waking up at the same time every day can help regulate your body’s internal clock.
5. Monitoring your blood sugar: If you’re particularly concerned about how your lifestyle impacts your blood sugar, consider keeping track of your glucose levels, especially at night. This can provide invaluable insights into your body’s responses.

(Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.)