Longer sleep might be associated with smaller body mass index, according to research reported by Reuters.

For the study, published in PLoS One, Gregory Potter of the School of Medicine at the University of Leeds in West Yorkshire, and his colleagues analyzed four years’ of data from a national diet and nutrition survey that also tracks other health and lifestyle habits among people in England, Northern Ireland, Scotland and Wales.

The available data included self-reported sleep records and food diaries for 1,615 adults, along with height and weight and blood pressure readings. In addition, about half of the participants agreed to provide blood samples so the study team could examine various measures of metabolic health such as cholesterol, blood sugar and thyroid hormone levels.

Researchers divided participants into three groups based on their average sleep duration. The bottom third had an average of 5.88 hours of sleep per night, with a range of plus or minus 52 minutes. The middle third had an average of 7.26 hours of sleep per night, plus or minus about 15 minutes, and the top third got an average of 8.44 hours of sleep at night, plus or minus 40 minutes.

The study team found that people in the top third for sleep duration had BMIs that were about two points lower – the equivalent of roughly 7 pounds (3.2 kilograms) – compared to people in the lowest third.

Read more at www.reuters.com