Irregular Sleep Tied to Obesity in Children, Adults, Study Indicates

A regular sleep schedule may decrease obesity risks, says an Italian study.

The results of a recently published observational study illustrate a positive correlation between an irregular sleep schedule and obesity rates in both children and adults.

Italian researchers distributed questionnaires evaluating sleep quality and physical composition to 71 adults, aged 29 to 42, and 128 children, aged 10 to 13. The 199 respondents’ weight, height, and body mass index (BMI) were measured along with their sleep patterns.

Survey queries included hours of sleep overall, the mode of falling asleep, and the quality of sleep experienced by respondents. Participants were also categorized into 1 of 4 weight groups (underweight, normal-weight, overweight, and obese) based on their BMIs.

The study, which ran from October 2016 through November 2017, compared male and female responses in the age-specific cohorts.

In the adult group, 32 participants were classified as obese and slept an average of 6.5 hours a night. Twenty-seven respondents were overweight and slept an average of 7 hours per night.

In comparison, the 23 respondents classified as normal weight slept an average of 8.3 hours per night, while underweight respondents slept an average of 8 hours per night. For both the male and female group, hours of sleep per night constituted a significant predictor of BMI score.

Notably, the results showed a significative positive correlation between age and BMI score in adult males. Adult males and females also exhibited a “significative negative correlation between sleep hours and BMI score.”

Of the 128 children surveyed, researchers again found “a significative negative correlation between sleep hours and BMI scores” in male and female respondents.

These findings are corroborated by previously published epidemiological and experimental studies.

“Several studies have shown that children aged 5 to 9 years who sleep less than 10 hours per night run a 1.5 to 2-fold risk of becoming obese compared to those who sleep properly; while adults that sleep less than 6 hours per night run a 50% risk of becoming obese,” researchers said.

Sleep irregularities can influence eating habits and physical activity, both main factors contributing to obesity. Sleep deprived individuals don’t expend as much energy as their fully rested peers, as they are less physically active. This can lead to potential weight gain.

Physiological factors like hormone imbalances are influenced by sleep irregularities and can also increase risks of obesity. One study showed “the reduction of sleep for 2 nights caused a reduction of 18% in leptin, a hormone with an anorectic effect, an increase of 28% in ghrelin, an obesifying factor, and an increase of about 25% in hunger, with a preference for the intake of foods containing carbohydrates with high caloric density over controls.”

Researchers stress the importance of a well-regulated sleep schedule among adults and children as a preventive measure against obesity and weight gain.


Bonanno L, Metro D, Papa M, et al. Assessment of sleep and obesity in adults and children. Medicine (Baltimore). 2019;98(46):e17642. doi: 10.1097/MD.0000000000017642.