This paper investigates how accountability pressures under No Child Left Behind (NCLB) may have affected students' rate of overweight. Schools facing pressure to improve academic outcomes may reallocate their efforts in ways that have unintended consequences for children's health. To examine the impact of school accountability, we create a unique panel dataset containing school-level data on test scores and students' weight outcomes from schools in Arkansas. We code schools as facing accountability pressures if they are on the margin of making Adequate Yearly Progress, measured by whether the school's minimum-scoring subgroup had a passing rate within 5 percentage points of the threshold. We find evidence of small effects of accountability pressures on the percent of students at a school who are overweight. This finding is little changed if we controlled for the school's lagged rate of overweight, or use alternative ways to identify schools facing NCLB pressure.