Hours slept in adolescence and risk of being overweight or obese

Recent research has examined the extent to which there is a relationship between the hours spent sleeping as an adolescent and the risk of being overweight or obese.

The study was carried out by the team led by Jesús Martínez Gómez, from the National Center for Cardiovascular Research (CNIC) in Spain. The results of this research have been presented at the Congress of the European Society of Cardiology, ESC 2022.

The study authors found that teens who sleep less than eight hours are more likely to be overweight or obese than those who get enough sleep.

In addition, research shows that those who sleep less are also more likely to have a combination of other unhealthy characteristics, including excess fat, high blood pressure, and abnormal blood lipid and glucose levels.

“Our study shows that most adolescents do not get enough sleep and that this is related to excess weight and the characteristics that promote weight gain, which could cause future problems,” explains Jesús Martínez Gómez. “We are currently investigating whether poor sleep habits are related to excessive use of electronic devices, which could explain why older adolescents sleep even less than younger ones.”

The research has examined the association between sleep duration and health in 1,229 adolescents in public secondary schools in Spain. The participants had an average age of 12 years at the beginning of the study, were evaluated for 4 years, and included approximately the same number of boys and girls.

The researchers measured sleep over seven days with a wearable activity tracker worn by each participant, at ages 12, 14 and 16.

To simplify the analysis, the study used 8 hours or more as optimal. Participants were classified as very short sleepers (less than 7 hours), short sleepers (7 to 8 hours), and optimal (8 hours or more).

Overweight and obesity were determined according to body mass index.

The researchers calculated a continuous metabolic syndrome score ranging from negative (healthier) to positive (worse) values ​​that included waist circumference, blood pressure, and blood glucose and lipid levels.

At age 12, only 34% of participants slept at least 8 hours a night, and this dropped to 23% and 19% at ages 14 and 16, respectively. Boys tended to sleep less than girls.

Teenagers who slept more also had better quality sleep, meaning they woke up less during the night and spent a greater proportion of their time sleeping in bed compared to those who slept less. The prevalence of overweight/obesity was 27%, 24%, and 21% at 12, 14, and 16 years, respectively.

Associations between sleep duration, overweight/obesity, and metabolic syndrome score were analyzed after accounting for other factors, such as whether or not the study subject smoked.

Compared with optimal sleepers, being overweight/obese was 21% and 72% more likely in very little sleepers at ages 12 and 14, respectively. Poor sleepers were 19% and 29% more likely to be overweight/obese compared to optimal sleepers at ages 12 and 14, respectively. In addition, both very little and little sleepers had higher average metabolic syndrome scores at ages 12 and 14 compared with optimal sleepers.

“The connections between lack of sleep and poor health were independent of energy intake and physical activity levels, indicating that sleep itself is important,” says Dr. Rodrigo Fernández-Jiménez, leader of group of the Imaging and Cardiovascular Health laboratory at the CNIC. “Excess weight and metabolic syndrome are ultimately associated with cardiovascular disease, which suggests that health promotion programs in schools should teach good sleep habits.”

Thus, he concludes, “fathers and mothers can set a good example by setting a consistent bedtime and limiting screen time at night. Public policies are also needed to address this global health problem.”

Sleeping less than necessary in adolescence is often linked to poor eating habits and an increased risk of becoming overweight or obese. (Photo: BYU)

Another important study in this line of research is carried out by the team led by Kara Duraccio, from Brigham Young University in the United States.

Previous studies have linked getting less sleep than needed in adolescence with an increased risk of poorer mental health, poor school grades, and behavioral problems.

But research by Duraccio and his colleagues indicates that getting less sleep than necessary in adolescence also increases the risk of gaining extra pounds and suffering from cardiometabolic diseases because adolescents adopt worse eating habits when they sleep less.

“Sleeping less than necessary increases the risk in adolescents that their consumption of foods rich in carbohydrates and added sugars, as well as that of sugary drinks, will become greater than when they get enough sleep,” emphasized Dr. Duraccio.

This study, titled “Losing sleep by staying up late leads adolescents to consume more carbohydrates and a higher glycemic load,” was published last December in the academic journal SLEEP. (Source: Amazings CNIC/NCYT)