Bouncing higher and higher on a trampoline, Breanna Bond reached out, touched her toes and flashed her mother a grin almost as wide as her outstretched arms.

The midair move marked another fitness milestone for the 10-year-old Clovis girl, who seven months ago weighed 186 pounds and was so out of shape she struggled when stooping to tie a shoe.

More than 50 pounds lighter and limber, Breanna showed off her trampoline skills on a recent afternoon. "Look, I'm going to do a flip," she said, turning upside down and landing on her feet.

"She just inspires me every day," Breanna's mother, Heidi Bond, said of her daughter's efforts.

In the central San Joaquin Valley, where more than 40% of fifth-, seventh- and ninth-graders are overweight or obese, it's easy to overlook the children who have toned up and slimmed down. But they're proof that childhood obesity can be beat, and they have lessons to share.

The formula the children have followed to become healthy and fit -- eating smaller portions and exercising more -- has long been proven to work. But no child would be overweight if living by those two principles were simple or easy, nutrition experts say. Children and their parents say bluntly that losing weight is tough. In the end, though, the struggle produces healthier children, making the calorie counting worth it, they say.

Alexander Flores, 16, of Fresno, has dropped almost 30 pounds off his 5-foot, 9-inch frame in the past few months, going from 209 pounds to 180 pounds. "When he weighs himself, he's ecstatic," said Alexander's mother, Melissa Flores.

Alexander works out every day, lifting weights and exercising, she said. He also has stopped eating late at night, and he eats smaller portions.

But in the beginning, it was hard to motivate her son, Flores said. It wasn't until his doctor warned him he was at risk for health problems that he began pushing himself, she said.

Alexander's not alone: Health experts say they are seeing children with weight-caused problems, such as diabetes, cardiovascular disease and joint problems usually seen only in adults.

Flores also has made changes to help Alexander. She added more whole grains, fruits and vegetables to the family diet. Luckily, Alexander seldom drank sodas or snacked on candy and chips, she said, but now he drinks fat-free milk. "The kids love it," she said. "To them, there's no difference."

Doing it together

Losing weight is a family affair, everyone agrees.

Some parents want to put overweight children on diets, but that doesn't work, said Tina Canales, a registered dietitian at the Clinica Sierra Vista office of the Women Infants and Children nutrition program. "It has to be the whole family eating healthier and exercising."

When city of Fresno Parks and Recreation enrolled 10- to 13-year-olds in a free six-week Healthy Lifestyles Fitness Program this summer, parent attendance at a twice-a-week nutrition class was mandatory.

That made a difference, said Sara Bosse, senior program manager for the University of California CalFresh nutrition education program, which partners with the city to run the summer camp. "You'll have parents with weak moments not wanting to employ what they've learned, and children are going to have weak moments, but they end up encouraging each other."

Julie and Jeff Pittenger began cooking more at their Fresno home when son Jared, 10, attended the fitness camp this summer. It paid off: Jared, at 5 feet, 7 inches, weighed almost 211 pounds when the six-week camp started and ended the camp weighing 202 pounds. Dietitians say a weight loss of between 1 and 3 pounds per month is considered a healthy pace for an overweight child.