For residents of Dorchester, Mattapan, and Roxbury, life is about to get a bit healthier.

After years of work, the Brigham and Women’s Center for Community Wellness, housed in Dorchester’s Sportsmen’s Tennis and Enrichment Center (STEC), opened its doors this week. The best part: It’s always free.

Building on STEC’s longtime community wellness programs, the new center aims to improve health in some of Boston’s most under-resourced neighborhoods, offering access to free programs, health screenings, and classes that will focus on major community issues such as heart disease and obesity.

“My general philosophy is you’ve got to do prevention not at a high-powered, world-class hospital, but out in the community where people live and work,” says Dr. Paul Ridker, a preventive cardiologist at Brigham and Women’s Hospital (BWH) and vice chair of STEC. “We’ve got to change the way we think about delivery of health and move it from the hospitals and into the communities.”

And Dorchester, Mattapan, and Roxbury are three communities highly in need of better health services. North Dorchester and Mattapan are the two most obese neighborhoods in Boston, and Roxbury has very high rates of diabetes hospitalizations. Between 2005 and 2010, heart disease rates in Mattapan increased by an incredible 30 percent.

The statistics go on, but the BWH/STEC partnership is hoping to tackle the specific issues that affect these neighborhoods head-on. Planned programming, set to begin this month, is tailored specifically to the issues facing local residents. In addition to fitness, it includes nutrition and weight loss counseling, diabetes control advice, smoking cessation groups, and basic adult education classes, all free of charge.

“This is a community that’s very close, geographically, to the Brigham and Women’s, but it’s quite a distance socially and economically,” Ridker says. “These are preventable issues later in life, but we’ve got to start with youth programs and adolescent programs and young adult programs to educate people about how they can avoid these consequences, and it just seemed the right thing to do in our backyard.”