Even as we face a childhood obesity epidemic, health experts warn that children are starving themselves more often — and younger than ever.

On one end of the spectrum, the Centers for Disease Control and Prevention warns that over the past three decades, the obesity rate has more than doubled for children ages 2 to 5 and for adolescents ages 12 to 19, and has more than tripled for children ages 6 to 11.

On the other end, more than 60 percent of elementary and middle school teachers say eating disorders are a problem in their schools, according to the National Association of Anorexia Nervosa and Associated Disorders (anad.org); the association also reports that the average age for the onset of anorexia is now 9 to 12, down from 13 to 17.

Each epidemic has its own tangled roots, but both signal dangerously unhealthy body images.

“They’re both about finding a sense of control with food, either never stopping eating or really controlling your food intake,” says Brian Alman, a clinical psychologist and author of several nutrition books, including “Keep It Off” (Plume). “Both are situations where kids feel out of control.”

Alman offers three tips to help a child shake his or her negative body image.

• Accept. “Tell your child, ‘I love you and accept you as you are,”‘ he says. “You can focus on the body, on the weight, but that’s not the issue. It’s emotional. It’s self-esteem. It’s dealing with peer pressure. There’s no sense bringing up how they physically look because that’s going to make them feel worse.”

If you sense a body image problem, Alman recommends initiating a conversation — don’t wait for your child to bring it up. And start positive.

“Talk about what’s right about your child,” he says. “What’s right about your body, what’s right about your ways of dealing with friends, school. That way the kid feels loved and accepted. They’ll know you’re a fan of theirs and they’ll bring up the negative stuff.”

• Open up. “Share your real experiences,” Alman says. “Tell your children about personal experiences you’ve encountered with body image, peer pressure and family pressure.”

This is a lot more effective when you, the parent, have healthy methods for dealing with stress, of course. “Maybe you’ve come up with a way to deal with cravings, so you have three or four other techniques besides overeating when you’re stressed,” he says. “Share that success with your kids.”

• Go shopping. “Find things that look great — colors, designs and styles,” Alman says. Gone are the days when the latest trends are only available for a specific body type. Take advantage of the wide range of sizes and treat your child to a few items that boost her or his self-esteem.

None of these techniques is meant to steer parents away from addressing the health impact of overeating or undereating, but Alman stresses that the emotional issues need to be addressed to solve the eating issues.

A recent article in Parenting: School Years magazine also suggested some tips for lowering your child’s risk for an eating disorder: Don’t harp on your own weight or appearance, which can reinforce the message that happiness is tied to appearance. Don’t be hypervigilant about banning sweets or other treats so children develop a fear of certain foods. And don’t comment excessively about other people’s body size, even as a compliment. “Hey, you look great! Have you lost weight?” can send signals that losing weight equals looking good.