Last week, Santa Rosa City Schools physical education teacher Tori Meredith was offered a morning treat by one of her students. It was a gesture both sweet and bewildering, she said.

"A first grader ... offered me a marshmallow. She had a whole bag of those jumbo marshmallows in the bag and she was eating them," Meredith said. "And she was obese."

Meredith, a vocal proponent of nutrition and exercise for young people, asked the young girl to hand over the bag.

The marshmallow example is extreme, she acknowledged. In most cases, families either aren't educated about healthful food choices, or their decisions are driven by economics.

"You can talk about junk food until you are blue in the face, but when McDonald's can make a meal for a family for $10 ..." she said. "You have families and that's all they can afford."

Meredith and retired family physician Joe Clendenin have been key players in establishing iDo26.2, a fledgling exercise program meant to inspire students to run at least 26.2 miles — the distance of a marathon — in increments over the course of the spring.

Santa Rosa City Schools adopted the program in October and backers are looking for financial support to get more than 10,000 students running next spring.

"The idea is that exercise clearly keeps you healthy, it helps you with your weight. It's not the only thing, to keep your weight down but it's a very important part of it," Clendenin said.

Efforts to get students and families to eat a more healthful diet are up against a mammoth fast food industry.

Taco Bell sold 100 million Doritos Locos Tacos in 10 weeks when the $1.29 item was launched in March.

Last year, the average American drank slightly under two sodas a day. Soft drinks are the the number one source of calories in American diets, according to the Center for Science in the Public Interest.

For Laurel Green, a veteran P.E. teacher at Brooks Elementary School in Windsor, physical education competes with music, computers and other subjects for time in the school day.

Green described Windsor as "very supportive" of physical education and still there is only time enough for 45 minutes of P.E. per week for each student, she said.

The state requires elementary students to spend 200 minutes every 10 days in physical education. But few schools meet that requirement, with steep budget cuts and increasing mandates on time spent on core subjects required under the federal No Child Left Behind law.

"It's a virtually impossible task to achieve," Green said.

At Brooks, fifth graders score better than the county average in both aerobic capacity and body composition.

Green focuses on rigorous exercise for 45 minutes. If it's raining, the kids are inside tumbling. If it's dry, they are working up a sweat, she said.

And she takes the time to speak with kids about their food choices when possible.

But, like Meredith, Green is acutely aware of the economic reality some of the families at Brooks and other area schools face.

"The processed food is cheaper, the unhealthy food is cheaper," she said. "We are living in a society that is run by an economic guide. If you have this much money, this is what you can buy."

Still, because local schools largely outpace federal nutrition guidelines for school breakfasts and lunches and nonprofit groups continue to push for increased exercise programs on campus, Green sees reason to remain optimistic.

"We are moving in a direction that is very unhealthy but I think there are enough hopeful programs happening and enough of that kind of energy that is still out there that I don't think it's a lost cause," she said.

(News Researcher Janet Balicki contributed to this story. Staff Writer Kerry Benefield writes an education blog at extracredit.blogs.pressdemocrat.com. She can be reached at 526-8671, kerry.benefield@press democrat.com or on Twitter @benefield.)