Children in nuclear disaster-hit Fukushima Prefecture are getting fatter due to lack of outdoor exercise amid daily radiation exposure limitations, the government said Tuesday in its school health report.

The preliminary report, released by the Ministry of Education, Culture, Sports, Science and Technology, showed an increase in children from kindergarten to high school age who weighed 20 percent more than the standard according to their height.

In Fukushima, 449 schools, or 56 percent of public schools, had curtailed outdoor activities during school time as of June last year to minimize exposure to radiation released from the crippled Fukushima No. 1 atomic plant. Such restrictions were still in place at 71 elementary and junior high schools this September, according to the prefectural board of education. It is believed schools based the amount of time they allowed kids to spend outdoors on local atmospheric radioactive fallout readings.