Longer naps lead to higher incidence of obesity, finds new study

The research indicates that napping for more than 30 minutes can be detrimental to health.
Loukia Papadopoulos
Napping for more than 30 minutes can be detrimental.jpg
Napping for more than 30 minutes can be detrimental.

Edwin Tan/iStock 

A team of Spanish scientists have found an unusual connection between long naps and obesity. The research was conducted with more than 3,000 Spaniards from Murcia.

This is according to a report by Euronews published on Sunday.

The study revealed that those who took long naps (more than 30 minutes) had a 2 percent higher body mass index, a 23 percent higher risk of obesity and a 40 percent higher risk of metabolic syndrome.

"Long naps are associated with an increase in the body mass index of metabolic syndrome, triglycerides, glucose and blood pressure,” said Marta Garaulet, author of the study and Professor of Physiology at the University of Murcia, Spain.

“In contrast, when the nap is short, we see it associated with a decrease in the probability of having high blood pressure, so in a way, the nap becomes protective.”

In 2022, the researcher led another study in the UK Biobank with 450,000 people. This work was carried out in a population with a median age of 60 years old "and where napping is not a habit of that culture,"told Euronews Garaulet. 

The scientist therefore wanted to study a sample of younger people with fewer diseases, but also in a country where there is a solid siesta culture and hot temperatures.

Previous studies have indicated that siesta genes are activated by heat.

"Summer temperatures activate the PER3 gene, which is the clock, nap-initiating gene,” said Garaulet.

Some people don't have siesta genetics, she further noted, “however, if you do, then this siesta gene might get activated in warmer areas, and you’ll feel like sleeping during the day".

The new Spanish study complemented the results from the English bank and led to some pretty interesting conclusions.

"There is a positive association between short naps and improved blood pressure, especially if you sleep in an armchair or on the sofa, not lying in bed," Garaulet told Euronews.

She further added that major postural changes throughout the day could increase blood pressure.

Another recently published study by Garaulet indicated that people who take long naps are more likely to have an altered rhythm in an enzyme called lipase, a key player in the digestion and metabolism of dietary fats.

But it’s not all bad. Previous studies have indicated that naps lead to higher productivity and lower blood pressure. So how do you balance the benefits with the risks? According to Garaulet it would seem that shorter naps in more erect positions are the key.