PORTLAND — The city’s public schools will receive more than $500,000 in federal stimulus money to launch a three-pronged effort to prevent childhood obesity, district officials announced today.

The two-year grant is part of $1.8 million received by Healthy Portland, a program of the city’s health and human services department. Maine received $4.3 million overall for obesity prevention programs.

The school district will use it’s money to improve the school lunch program, increase nutrition education and promote physical activity.

“This award will help us make a real difference in improving the nutrition and health of Portland’s schoolchildren,” said Chanda Turner, the district’s school health coordinator.

The district plans to use the grant to install more salad bars, serve more locally produced foods and provide nutrition information about school menu items in pamphlets and on its Web site, portlandschools.org.

“We will save money on our food service program, immediately and over the long term, while making changes that promote healthier eating,” said Ron Adams, the district’s director of food services.

In addition, classes will create short video podcasts showing how to perform exercises, dance routines and other physical activities that also will be posted on the Web site. Students, teachers and community members will be encouraged to integrate physical activity into their daily schedules.

The school initiatives will dovetail with projects implemented by grant partners, including Portland Trails, WinterKids, Let’s Go! and the Maine Centers for Disease Control and Prevention.