Can Lack of Sleep Affect Your Blood Sugar?

Researchers asked volunteers to wear fitness bands to record how long and how well they slept. They then tested how effectively their bodies controlled blood glucose after food was eaten the following morning.

Going to bed later and having less quality sleep was linked with poorer blood sugar control after eating breakfast the next day. This was particularly pronounced with high carbohydrate or high sugar breakfasts like sweet cereals or croissants. These tax your body’s homeostatic mechanisms because the sugar they contain is released rapidly into your bloodstream. Even if the night owls slept later the next morning, getting the same amount of sleep as the ones who turned in early, their blood sugar control the following morning was still worse.

Researchers also found a change from a person’s usual bedtime routine, even for just one day, led to poorer glucose control. So, if you usually go to bed around 10.30pm during the week, staying up until midnight at the weekend will disrupt your blood sugar control.

These discoveries support other research finding later bedtimes are linked to chronic diseases such as heart disease, type 2 diabetes and obesity. One study revealed people who usually go to bed after 11pm have a 12% higher risk of heart disease than those whose bedtimes were between 10pm and 11pm. The risk rose to 25% higher in people who habitually went to bed after midnight. Constant peaking and troughing of blood sugar damages blood vessels around the heart, putting you at an increased risk of these diseases over time.

It’s all very well going to bed early, but what if you don’t sleep well? Good sleep quality, as measured by whether you’re able to stay asleep for most of the night, also reduces those large blood sugar increases after breakfast the next day. People who don’t sleep well have more blood glucose fluctuations, particularly after eating sugary foods, often those very foods craved after a poor night’s sleep.