Children exercise at a summer camp for overweight minors in Qingdao, Shandong province, in July. Photos by He Yi / For China Daily

Childhood obesity has dramatically increased in rural parts of Shandong province, a study has found.

The prevalence of overweight boys has increased from 0.74 percent in 1985 to 16.35 percent in 2014, while 13.91 percent of girls are now overweight, compared with 1.45 percent three decades ago, the Xinhua News Agency reported, citing a study conducted by Shandong Center for Disease Control and Prevention.

Over the same time period, the prevalence of obesity in boys soared to 17.20 percent from 0.03 percent, and to 9.11 percent from 0.12 percent in girls, the study shows.

Data for the study was obtained from six cross-sectional surveys conducted in 1985, 1995, 2000, 2005, 2010 and 2014 on 27,840 rural students ages 7 to 18 in Shandong province.

It defined obese and overweight using criteria from the Working Group on Obesity in China, the International Obesity Task Force and the World Health Organization.

Another survey conducted on 1,817 rural children ages three to seven in Zhengzhou, Henan province, showed 105 children were obese, a report by the Beijing Times said on Monday.

The survey showed that only 6.77 percent of parents would prohibit their children from drinking sugary beverages or eating food that was high in calories.

"Many rural parents, especially the elderly, have no idea that obesity will lead to many diseases," Zhuang Hao from Henan Provincial Tumor Hospital was quoted as saying by the Beijing Times.