SINGAPORE, Oct. 27 (Xinhua) -- Boys who consistently slept nine hours or more each night throughout the week had a 51 percent lower risk of obesity and significantly less abdominal fat compared to those with insufficient sleep, according to a new study by Singapore's Agency for Science, Technology and Research.

The study, involving 638 children from Singapore's three major ethnic groups, combined caregiver-reported sleep data and wearable activity tracker readings with magnetic resonance imaging (MRI) scans to assess abdominal fat, the agency said in a release on Monday.

Findings showed that boys who met the recommended sleep duration had notably less fat in all measured areas, including both fat under the skin and fat around internal organs. They also exhibited lower levels of an inflammation marker in the blood linked to chronic inflammation and heart disease risk.

A similar but weaker association was found among girls, suggesting biological or behavioral differences in how sleep affects fat storage.

Abdominal fat, particularly fat around internal organs, is closely linked to metabolic diseases such as type 2 diabetes and cardiovascular disease, the study noted.

Researchers also observed that many school-age children attempted to make up for insufficient weekday sleep by sleeping longer on weekends. However, meeting sleep recommendations only on weekends did not reduce obesity risk or abdominal fat levels.

"This finding has important implications for parents, schools, and policymakers," said the study's senior author Shirong Cai. "It suggests that consistent sleep habits throughout the week are what matters for protecting children's metabolic health, not just letting children sleep in on weekends." ■