People who used to work nights don’t seem to have more health problems like diabetes or heart disease risks later on than people who never worked nights—even when you account for their age and medicines they take.

People who work nights don’t seem to have worse health markers like weight, blood pressure, or blood sugar compared to similar people who only work days—so night shifts probably don’t mess up your metabolism, heart, or immune system in this group of Germans.

Working nights might affect your health differently depending on things like your gender, when you naturally feel awake or sleepy, or how much money you make — but this study didn’t check any of those things, so we can’t fully explain why other studies have found different results.

People who work nights or irregular shifts are more likely to develop a fatty liver condition, especially if they do it for a long time or often — this might be because their body’s internal clock gets messed up.

Working irregular hours or not sleeping well can mess up your body’s internal clock, which in turn hurts your metabolism and liver — making it harder for your body to process food and stay healthy.

Korean women who are overweight and work nights or rotating shifts are much more likely to have high insulin levels than overweight women who work regular daytime hours, which might mean their bodies have a harder time managing blood sugar.