Despite California’s image as a health-obsessed state, most Californian adults are obese or overweight, and the flab and physical inactivity cost $22 billion annually, a report released on Tuesday said.

An aging population, increasingly sedentary lifestyles, a car culture paired with junk-food-peddling gasoline stations and an abundance of fast-food restaurants in low-income areas are among the major reasons Californians are becoming larger, according to the California Department of Health Services.

“More than half of California adults now are overweight or already obese,” the report said.

“We’re getting to the point where we’re joining the highest obesity states,” said Susan Foerster, chief of the health service’s cancer prevention and nutrition section. “Employers are bearing the brunt of the cost.”

Obesity has become one of the U.S. health establishment’s top concerns because it afflicts all age groups, is the source of many health problems and is on the rise amid soaring health-care costs.

A modest improvement in physical activity could cut costs imposed on California by its flab, the Tuesday study showed. A 5 percent improvement in rates of physical activity and weight loss over five years could save more than $6 billion, and a 10 percent improvement could save nearly $13 billion, the report said.

Shaving extra inches from waistlines would improve the bottom lines of California employers.

“The total lost productivity cost relevant to physical inactivity is nearly $7.5 billion, and the cost of obesity is approximately $3.4 billion,” the report said.

With medical care, prescription drug and workers’ compensation costs added to lost productivity, the overall cost imposed on California by physically inactive, overweight and obese adults rises to $22 billion annually, it said.

“On average, a staggering three weeks or more per year of lost productivity can be attributed to the designated risk factors, over 50 percent more time than the average 14.2 days vacation and holiday leave that United States private sector employees averaged in 2000,” the report added.