The research, published recently in the journal Nature Communications, found that sleep duration decreases during early adulthood until age 33, before it increases again at age 53.
In the study, scientists, including those from the University of Lyon in France, assessed 730,187 participants from 63 countries, to uncover how sleep patterns change throughout the human lifespan and how they vary across different countries.
Participants in the study played the citizen science game Sea Hero Quest mobile game that was designed for neuroscience research.
Those playing the game were surveyed about demographic characteristics as well as questions on their sleep patterns.
The data suggest that people across the study sample sleep an average of about seven hours per night, with women sleeping 7.5 minutes longer than men on average.
Researchers also found that the youngest participants in the sample – minimum age 19 – slept the most.
Based on the data, they say sleep duration likely declines throughout people’s 20s and early 30s before plateauing until their early 50s and increasing again.
Scientists say at age 33 the declining sleep plateaus, and at 53 sleep duration increases again – a pattern that was found to be the same for men and women, and across countries and education levels.
They say the decline in sleep during mid-life is likely due to the demands of childcare and working life.
“Previous studies have found associations between age and sleep duration, but ours is the first large study to identify these three distinct phases across the life course,” study co-author Hugo Spiers said in a statement.
“We found that across the globe, people sleep less during mid-adulthood, but average sleep duration varies between regions and between countries,” Dr Spiers said.
People in the UK reported sleeping slightly less than the average, as well as those in countries closer to the equator.
Participants from Eastern European countries like Albania, Slovakia, Romania, and the Czech Republic, reported 20-40 minutes extra sleep per night, the study noted.
“Here, using reported sleep duration from 730,187 participants across 63 countries, we find three distinct phases in the adult human life-course: early adulthood (19-33yrs), mid-adulthood (34-53yrs), and late adulthood (54+yrs),” scientists wrote in the study.
“They appear stable across culture, gender, education and other demographics,” they added.