Taking long midday naps could be associated with a higher risk of type 2 diabetes. The Japanese study found that those who took longer naps had a 45 percent higher risk of type 2 diabetes, compared to those who took short naps.
Napping less than an hour did not contribute to a higher risk of type 2 diabetes.
The study does not reveal cause-and-effect relationship, but rather suggests that taking long naps is often associated with other lifestyle habits that further increase the risk of developing type 2 diabetes – for example, lack of physical activity.
The researchers analyzed data from over 300,000 people involved in 21 published studies. They found that naps longer than an hour were associated with a 45 percent higher risk of type 2 diabetes, while shorter naps (or no napping at all) posed no additional risk of diabetes.
Further research is required to better understand this association.