Study reveals why it may not be a good idea to take lengthy naps

‘Not all siestas are the same’

People who take long naps are at a greater likelihood of having metabolic syndromes like obesity and high blood pressure compared to those who do not take them, according to a new study.

Many people across the world have a tendency to take midday naps, but despite its potential to impact sleep quality and metabolic processes, the link between these siestas and health remains unclear, said researchers from Brigham and Women’s Hospital in the US.

Researchers have sought to understand the link between lifestyle choices such as taking siestas and the effect they have on the body’s metabolic processes.

One such process is obesity, a growing concern that affects the health of over a billion people around the world. Fat accumulation in the body is also associated with how food is digested during metabolic processes.

And in the latest study, published recently in the journal Obesity, scientists have evaluated the link between siestas, their duration and obesity in over 3,000 adults from a Mediterranean population.

Participants who took naps of 30 minutes or longer were found more likely to have a higher body mass index, higher blood pressure and a cluster of other conditions linked to heart disease and diabetes compared to those without siestas.

However, in those who had short siestas, or “power naps”, this increased risk for obesity and other metabolic changes were not present.

Short nap-takers were less likely to have elevated blood pressure than those who took no siestas, according to the study.

“Not all siestas are the same. The length of time, position of sleep, and other specific factors can affect the health outcomes of a nap,” said senior author Marta Garaulet said in a statement.

In the research, scientists examined data from 3,275 adults in the Mediterranean population from the Spanish region of Murcia, including their baseline metabolic traits and additional information also collected regarding their naps and other lifestyle factors.

The people’s data was then categorised into those with no siestas, shorter than 30 minutes and longer than 30 minutes.

Researchers found the long siesta-takers had a higher body mass index and were more likely to have metabolic syndromes than those who did not take such naps.

Compared to the no-siesta group, the long nap takers were also found to have higher values of fasting glucose levels and blood pressure.

Long siestas, researchers said, were associated with later nightly sleep timing and food timing.

This group also had increased energy intake at lunch and cigarette smoking, according to the study.

However, researchers cautioned that the findings are observational, adding that it may be possible that some factors could be a consequence of obesity itself and not siestas.

Scientists call for further research to assess whether short siestas are advantageous over a long one, particularly for people with habits such as having delayed meals and sleep schedules, or for those who smoke.

“If future studies further substantiate the advantages of shorter siestas, I think that that could be the driving force behind the uncovering of optimal nap durations, and a cultural shift in the recognition of the long-term health effects and productivity increases that can amount from this lifestyle behavior,” study co-author Frank Scheer said.