The group, called Mission: Readiness, released a report that found that about 12 percent of active-duty service members were obese based on height and weight, a number that has risen 61 percent since 2002. The report said the extra weight cost the military about $1.5 billion annually in health care spending, as well as the expenses of replacing unfit soldiers, Marines, sailors and airmen. Service members who are out of shape are unlikely to be able to carry heavy equipment or engage in the prolonged physical activity needed in combat, members of the group said.

The report is the third released since 2010 by the group, which has tried to focus attention on obesity in the United States and its effect on the armed forces. While previous reports have focused on the military’s difficulty finding recruits fit enough to fight, Wednesday’s report was the first to bring attention to the impact of extra pounds on millions of active-duty service members.

“This really is a problem that has gone unreported,” said Casey W. Coane, a retired Navy rear admiral and a member of Mission: Readiness. “And it is impacting our ability to defend this nation.”