Associations between the "Double Reduction" policy and physical activity and overweight/obesity among Chinese school-aged children: a quasi-experimental difference-in-differences analysis.
Yu W & Zhang B • Frontiers in public health • 2026
The Double Reduction policy coincided with measurable improvements in physical activity and weight status among Chinese school-aged children, with compulsory-education students gaining 43.1 weekly MVPA minutes and showing a 3.9 percentage-point lower overweight/obesity prevalence relative to senior high school comparison students.
Key Findings
Results
The Double Reduction policy was associated with 43.1 additional minutes per week of moderate-to-vigorous physical activity (MVPA) among compulsory education students relative to the comparison group.
The estimate had a 95% CI of 33.8-52.3 and p < 0.001.
The design was a difference-in-differences analysis using CFPS waves from 2018, 2020, and 2022.
The treatment group was students in grades 1-9; the comparison group was senior high school students in grades 10-12, who were not covered by the policy.
MVPA was self-reported in weekly minutes.
Results
The policy was associated with a 3.9 percentage-point reduction in overweight/obesity among compulsory education students relative to the comparison group.
The 95% CI was -7.2 to -0.6, with p = 0.022.
Overweight/obesity was defined by age- and sex-specific BMI z-scores using the WHO 2007 reference.
The analytical sample comprised 4,237 students contributing 10,799 person-wave observations.
Results
Estimated associations were larger among primary school students and among children whose parents had lower educational attainment.
These were reported as heterogeneity (subgroup) results.
The abstract does not give subgroup-specific estimates.
Results
The pre-policy (2018) interaction term was small and not statistically significant for either outcome, but the number of pre-policy waves limits the power of the pre-trend test.
Event-study specifications were used to assess pre-trends.
Only two pre-policy waves were available, offering limited power for testing pre-trends.
Results
The estimates were stable across alternative specifications and robustness checks.
Checks included a balanced panel, propensity-score weighting, longitudinal survey weights, and placebo tests.
Estimates were reported as similar under balanced-panel, propensity-score-weighted, survey-weighted, and placebo specifications.
Background
The study used the 2021 Double Reduction policy as a natural experiment to examine physical activity and weight outcomes, which previous evaluations had mostly not addressed.
The policy was implemented in July 2021 to ease homework burden and curb off-campus tutoring in compulsory education.
Earlier evaluations focused mainly on academic and mental health outcomes.
Conclusions
The authors conclude that education policies relieving academic burden may carry collateral public health benefits.
They state the policy coincided with measurable improvements in physical activity and weight status.
They suggest such policies deserve explicit consideration in child health strategies.
What This Means
This study looked at whether China's 2021 "Double Reduction" policy, which reduced homework and restricted off-campus tutoring for students in grades 1-9, was linked to changes in children's physical activity and weight. Using national survey data from 2018, 2020, and 2022, the researchers compared students covered by the policy with senior high school students (grades 10-12), who were not covered, and tracked how each group changed over time.
Compared with the older students, children in grades 1-9 reported about 43 more minutes of moderate-to-vigorous physical activity per week after the policy. They also had a 3.9 percentage-point lower rate of overweight or obesity. The differences were larger among primary school children and among children whose parents had less education. Several robustness checks gave similar results, and the pre-policy differences between groups were small.
This research suggests that policies aimed at reducing academic pressure may also have benefits for children's physical health. However, the study is observational and relies on self-reported physical activity. Only two time points preceded the policy, which limits how firmly the authors can rule out earlier differing trends. The findings show an association, not proof that the policy caused the changes.
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Yu W, Zhang B. (2026). Associations between the "Double Reduction" policy and physical activity and overweight/obesity among Chinese school-aged children: a quasi-experimental difference-in-differences analysis.. Frontiers in public health. https://doi.org/10.3389/fpubh.2026.1963763