“Stand up straight!” “Don’t eat that junk food!” “Honey, you look great!” As a parent, do you ever hear yourself nagging your children with these statements? All well-meaning, of course.

Conversely, do you ever wonder about what simultaneous messages are screaming through your children’s heads? “I’m so fat!” “I want more muscles.” “I look so great in this outfit!” “I’m so ugly.”

Kids develop a self-image of their body—positive or negative—long before the tween/teen years, which is when parents typically expect such issues to arise. Lyndsay Elliott, a clinical psychologist in Newport Beach, Calif., says that today, children as young as 8 or 9 are creating an image of their body...and one that’s not always positive.

“We’re seeing a whole influx of kids being diagnosed with eating disorders, both boys and girls,” Elliott says. “Sometimes with boys, issues are minimized. But boys have issues, too, affecting them equally.”

Influenced by classmates as well as images portrayed on TV, in magazines, on websites, and in video games, kids are taking a mental snapshot of themselves, and it’s not always pretty. In an effort to shape themselves into what they perceive to be a more appealing picture, some take extreme measures that are not healthy, like excessive bodybuilding or persistent dieting that can lead to conditions like anorexia.

As a parent, guiding your child through these critical years when his body and self-image are changing and developing can be overwhelming. Where do you start? And what if you’re not the perfect example yourself?

The good news? Your child can create a positive environment to frame her self-image, one that you can help her build and maintain. That’s because, experts say, it doesn’t begin in the gym, at the cafeteria lunch table, or at the chic boutique; instead, it begins in her head. And yours.

By focusing less on physical aspects—weight, amount of food consumed, muscle—and more on the positive characteristics he possesses—kindness, passion, and humor, which will shape him for life—you can help your child develop a healthy, positive self-image from a young age, an image that is reflected both in his body and in how he treats himself and others.

These six tips, from child experts and authors who have written about self-image, can help your child begin heading in the right direction toward a lifelong positive body image.

  1. Repeat after me. Don’t be surprised if your child resists doing affirmations. Yes, they’re “new agey,” which she might not like, but there might be another reason. Affirmations are about “recognizing—declaring the truth of something,” according to Jill Zimmerman Rutledge, author of Picture Perfect: What You Need To Feel Better About Your Body. Your daughter may not yet see, or believe, what she’s affirming; all the more reason to start with the image inside her head. Zimmerman Rutledge, an Illinois-based specialist in eating disorders and body image problems for more than 30 years, recommends practicing affirmations. She says she always tells kids one of her favorite affirmations, which came from tennis pro Monica Seles: “Whatever my weight is, that’s fine. As long as I am able to move and feel good, it doesn’t matter.”

  2. Stand up straight—really. Who hasn’t harped on a son or daughter to stop slouching? There’s good reason why, according to Rob Williams, a kinesiologist, posture specialist, and founder of Performance Posture in Vancouver, British Columbia. Not only can self-image improve with proper posture; proper body alignment and posture also can be the keys to improved physical health and athletic performance. Williams, who has worked with everyone from NFL quarterbacks to professional skiers to TV actresses like Tori Spelling, has found that proper posture even reduces a child’s chances of being bullied. Posture enhances how she is perceived by peers and superiors, and perhaps one day will be perceived by colleagues and superiors in the boardroom, he says. Research validates the immediate, positive effects of proper alignment; by improving and focusing on your posture, Williams says, “you’ll change your outlook and your mood instantly.”

  3. Paint praise in specific ways. Before applauding your daughter with a one-size-fits-all “Great job, honey!” think how she might feel if you said something like “You know, you’re really good at...” or “You seem to really know....” Commenting on specific internal qualities instills self-assuredness in your child, says Elliott. Make sure to reward your child’s effort and completion, she adds, not just the outcome.

  4. Find a passion and exercise it. “We forget to pay attention to people’s souls,” says Dr. Carol Francis, Phys.D., a psychologist in Torrance, Calif. Francis recommends that parents celebrate the character qualities in their children, like compassion, kindness, and intelligence. She also recommends helping children find and develop their passions as a way to define themselves. “If a child doesn’t have [his] own interests,” she warns, “he’ll end up following someone else.”

  5. For boys, forget black-and-white thinking. While both boys and girls can misperceive their weight, girls typically think they’re heavier than they actually are whereas boys think they’re lighter and skinnier than they actually are, says Dr. Will Courtenay, Ph.D., author of Dying To Be Men. Courtenay says that’s because “there’s a cultural belief that guys should be big and muscular.” As a result, one in four men of normal weight thinks he’s underweight, and nearly half of overweight men think their weight is normal. Try to get your son to think about his body in the “gray zone,” Courtenay says, and avoid “black-and-white thinking.” Talk to him about the fact that most people don’t have perfect—or perfectly awful—bodies. If your son is building his body to attract girls, let him know that women like less muscle, about 15 to 20 pounds less, than men think women like.

  6. Be forgiving when your child embarks on an exercise program. Len Saunders, author of Keeping Kids Fit, suggests that parents help their kids reframe their efforts in a more realistic light so they’ll keep plugging away. After 25 years focused on fighting childhood obesity through health and fitness programs, Saunders says he’s heard it all. When your son complains “I can’t do it” shortly after beginning his new exercise program, Saunders recommends asking, “How long have you done it?” Is his answer just five days? Perhaps five weeks? It doesn’t matter, Saunders says—applaud his effort. Acknowledge that it takes time. “Kids expect instant change, like what they see on the 20-second TV commercials,” he says. “That’s a fantasy world. It doesn’t happen that way.” Similarly, when your daughter bemoans eating some cookies, help her realize any positive changes she’s made—“You ate just two cookies, not 10!”—and build on that as a stepping-stone. “It’s amazing how much power words can have,” Saunders says.

Freelance writer Kathy Shiels Tully and her husband live with their two daughters north of Boston.