In France, 8.5% of adults are obese. As for overweight, this rate is around 30%. “Overweight and obesity result from an imbalance between energy intake (diet) and energy expenditure (physical activity)” explains the World Health Organization (WHO), which specifies that “In most cases, obesity is a multifactorial disease due to obesogenic environments, psychosocial factors and genetic variants.” Prevention is therefore a public health issue.
Among the reflexes to adopt, we can list a balanced dieta regular sports practicebut also good sleep habits. It is on this last point that researchers from the University of Health and Sciences of Oregon, in the United States, looked. They noted that poor quality sleep can lead to weight gain and different consequences in men and women. Their results are published in the Journal of Clinical Endocrinology & Metabolism.
Going to bed after ignoring sleep signals may increase risk of weight gain
To arrive at these results, the researchers relied on a panel of 30 people with a body mass index (BMI) greater than 25, which classified them in the category of overweight or obese people. As a reminder, BMI is defined by the WHO as “a simple measure of weight for height commonly used to estimate overweight and obesity.” It is calculated by dividing weight by height squared. You can calculate your BMI using our online tool.
The researchers first collected saliva samples in the early evening in a laboratory, which, after analysis, allowed them to determine the natural production of melatonin, “a small molecule synthesized in our brain, whose soporific action helps us fall asleep”, notes Inserm. The time of its production can vary depending on the person. Subsequently, the participants noted their sleep habits for a week.
Based on the results, the researchers divided the participants into two categories: those who usually went to bed close to the time of melatonin production and those who went to bed at a later time with a longer duration between the onset of melatonin and sleep.
Researchers call for “go to bed when you are tired or put your screen aside in the evening”
According to the researchers, going to bed shortly after the body starts producing melatonin (a sleep-related hormone) could be a sign that the person is staying up later than their biological clock recommends. This is done by ignoring their body’s natural sleep signals before going to sleep.
Experts have also noted differences between men and women.. In fact, men who had poor sleeping habits “had higher rates of abdominal fat and fatty triglycerides in the blood, as well as higher overall metabolic syndrome risk scores.” Among women, this group had “an overall body fat percentage, a blood sugar level and a higher resting heart rate.”
“This study confirms the importance of good sleep habits”, explains in a press release Brooke Shafer, postdoctoral researcher in the Sleep, Chronobiology and Health Laboratory at the OHSU School of Nursing. “Sleep practices, such as going to bed when you’re tired or putting down your screens in the evening, can help promote good overall health,” he concludes.
Sources :
- Circadian alignment, cardiometabolic disease, and sex specific differences in adults with overweight/obesity – Journal of Clinical Endocrinology & Metabolism (20/08/2024)
- Good sleep habits important for overweight adults, OHSU study suggests – Oregon Health & Science University (23/08/2024).
- Obesity and overweight – WHO – March 2024
- Chronobiology / The 24 hours chrono of the organization National Institute of Health and Medical Research (Inserm) – 2018
