Belgian youth activity patterns shifted unevenly between 2014-15 and 2022-23
Physical activity in Belgian children and adolescents did not collapse across the board, but it also did not move far enough to change the public health picture. Between 2014-15 and 2022-23, accelerometer data from the Belgian Food Consumption Survey showed a mixed pattern: some girls became more active on weekdays, yet sedentary time rose in several age-sex strata and overall adherence to international activity guidelines stayed close to 40%.
The comparison is built on two nationally relevant samples of young people aged 5–17 years: 1,043 participants in 2014-15 and 790 in 2022-23. Because the measurements came from accelerometers rather than self-report, the findings carry more weight than the usual recall-based estimates that often blur short bursts of movement, screen-bound stillness, and after-school activity. In practical terms, the data capture how children and adolescents actually moved during the week and on weekends, not how they remembered moving.
A small rise in movement did not erase a larger burden of stillness.
Weekday gains in girls contrasted with stable or weaker patterns in boys
Weekday light physical activity increased by 16 minutes per day among girls, while moderate-to-vigorous physical activity rose by 6 minutes per day. Both changes were statistically significant. On the surface, those are encouraging shifts, especially because moderate-to-vigorous physical activity is the intensity most closely tied to cardiorespiratory fitness, metabolic health, and long-term risk reduction. A modest rise in this category can matter biologically, because even short periods of running, sport, and brisk play can improve insulin sensitivity and counter the cumulative effects of inactivity.
Boys did not show the same weekday improvement. Their light activity and moderate-to-vigorous activity remained broadly stable, which suggests the behavioral pattern was not uniformly changing across the population. The sex difference raises familiar questions about access to organized sport, after-school routines, peer norms, and the ways school-aged children divide their day between structured activity and sitting. It also suggests that one broad youth strategy may miss the subgroups most likely to respond to different social and environmental cues.
Weekend behavior was less reassuring. Girls showed a non-significant increase in moderate-to-vigorous activity of 4 minutes per day, while boys aged 10–13 years had a non-significant decrease in light activity of 22 minutes per day. These weekend signals are less definitive statistically, but they point in the same direction: movement patterns are not settling into a healthier rhythm outside the school week.
Sedentary time rose where later childhood often becomes more vulnerable
Sedentary time did not change significantly on weekdays overall, but weekend sitting time increased in several groups. Adolescents aged 10–13 years recorded an extra 23 minutes per day, girls aged 5–9 years added 24 minutes per day, and boys aged 10–13 years added 40 minutes per day, with the last estimate narrowly missing conventional statistical significance.
Those age bands matter. Early adolescence is often when physical activity begins to drop and sedentary routines harden, driven by school demands, screen exposure, changing social priorities, and reduced spontaneous play. An increase of 23 to 40 minutes may look modest in isolation, yet it is biologically meaningful when layered onto a full day already dominated by sitting. More sedentary time means fewer muscle contractions, lower energy expenditure, and less frequent interruption of glucose-storing, circulation-slowing behavior. Over months and years, that pattern can shape cardiometabolic risk even before any clinical disease becomes visible.
The measurements make the public health challenge harder to dismiss. Belgian children and adolescents were not simply failing to meet an abstract recommendation; many were spending too much of the day in a posture pattern that works against metabolic flexibility and habitual movement. Screen time was not directly quantified in the summary, but the weekend rise in sedentary time is consistent with the broader behavioral drift seen in many pediatric populations.
Guideline adherence barely moved, leaving most young people below target
Overall adherence to the international benchmark of at least 60 minutes of moderate-to-vigorous activity per day on average, plus vigorous activity on at least 3 days per week, remained essentially unchanged: 37.6% in 2014-15 and 39.9% in 2022-23. Among girls, estimated adherence increased from 23.4% to 30.4%, but the difference did not reach statistical significance.
This is the most important result in the study because it shows how incremental gains can fail to shift population coverage. A slight improvement in girls’ weekday activity was not enough to move the overall adherence rate meaningfully, and no subgroup crossed into anything resembling universal compliance. In other words, the population curve stayed stubbornly flat where it matters most: the share of young people meeting a threshold linked to healthier growth trajectories.
The findings also reinforce why guidelines should not be treated as a passive educational message. Children do not naturally accumulate 60 minutes of moderate-to-vigorous activity unless schools, families, neighborhoods, and leisure settings make movement easier than sitting. If weekend sedentary time climbs while weekday activity improves only modestly, the daily average can look deceptively stable while the underlying behavior remains unhealthy.
Surveillance still matters because behavior change is uneven and incomplete
The investigators used design-based statistical methods and stratified analyses by age and sex, which strengthens confidence that the observed differences reflect real subgroup patterns rather than a single averaged trend. The use of two survey waves also provides a useful temporal window across nearly a decade, a period long enough for social changes in children’s routines to accumulate.
Even so, the results leave a clear clinical and public health problem in place. Most participants did not meet the recommended activity threshold, and the gains that did emerge were selective rather than broad-based. Girls improved on weekday activity, but boys did not. Sedentary time increased on weekends in younger children and early adolescents, the very stages when healthy habits should be consolidating rather than eroding.
For clinicians, educators, and public health teams, the message is concrete. Youth movement patterns need repeated measurement, because a single national estimate can conceal sharp differences by age, sex, and day of the week. The current data argue for targeted intervention during the transition from childhood into adolescence, when sedentary habits appear to stiffen and when even small reductions in movement can become entrenched.
The study closes without offering a therapeutic fix, and that absence is itself informative: surveillance is identifying the problem faster than policy and school-based interventions are solving it. The next challenge is not proving that Belgian youth need to move more; it is finding which settings can reverse the weekend rise in sedentary time and sustain the modest weekday gains already seen in girls.