Does a lack of sleep actually affect blood sugar levels?

Yes, sleep plays a massive role in blood sugar regulation. When you are sleep-deprived, your body experiences physiological stress and releases higher levels of hormones like cortisol. This surge in stress hormones directly decreases insulin sensitivity, meaning your body has to work much harder to process glucose. Even just a few nights of poor sleep can lead to noticeably higher morning blood sugar readings and increased cravings for quick-energy, high-carbohydrate foods throughout the day.