Fewer hours you snooze the heavier you’re likely to be

Not getting enough sleep? It could be adding to your waistline.

A United Kingdom study has found that people who sleep about six hours a night had a waist 3.05 centimetres larger than those getting nine hours of sleep a night.

The research, which was led by Laura Hardie of the University of Leeds, looked at 1,615 adults who reported how long they slept and kept records of food intake. Participants had blood samples taken and their weight, waist measurement and blood pressure recorded. The researchers also took into account age, ethnicity, sex, smoking and socioeconomic status. The findings were published in the journal PLOS One.

“Because we found that adults who reported sleeping less than their peers were more likely to be overweight or obese, our findings highlight the importance of getting enough sleep,” Hardie told the ScienceDaily.com website.

“How much sleep we need differs between people,” she added, “but the current consensus is that seven to nine hours is best for most adults.”

Lack of sleep was also linked to reduced levels of HDL cholesterol — the “good” cholesterol — a factor that can increase the risk of heart disease.

However, according to ScienceDaily, the study did not find any relationship between shortened sleep and a less healthy diet, a fact that surprised the researchers. Other studies have suggested that shortened sleep can lead to poor dietary choices.

As to why lack of shut-eye can increase weight, another study, which took place at the University of Chicago in 2012, found that signals from the brain that control appetite are affected by lack of sleep, the website reported. In particular, the hormones ghrelin, which increases appetite, and leptin, which indicates when the body is satiated, are impacted.

Another of the Leeds researchers, Greg Potter, said the number of people with obesity worldwide has more than doubled since 1980.

“Obesity contributes to the development of many diseases, most notably type 2 diabetes,” he told the website. “Understanding why people gain weight has crucial implications for public health.”