Parents often struggle with tough questions, such as when are kids old enough to stay at home alone or start dating? But how about what age is appropriate for a kid to start dieting? Experts say, unless there’s a medical reason for a child to be put on a special diet, the right answer is “never.”

bad news for growth

Young adolescence is a period of active growth, which is why dieting during this age is risky, explains Dr. Diane Sacks, a Toronto pediatrician and a member of the Canadian Paediatric Society’s Community Paediatrics Committee. “Growth is a metabolic process, so if kids don’t consume enough of the nutrients they need during this period, the body goes into breakdown mode instead, or a catabolic phase. Calcium and iron are really key nutrients, and they’re hard to get in sufficient amounts if you restrict calories.”

If kids miss out on this vital growth period, it can cause slowed or stunted growth and delay puberty. “Increased bone density, the beginning of menstruation, as well as increased height and weight gain occur naturally during puberty and can be impacted by dieting,” says Sarah Chapman, a clinical dietitian at the Janeway Children’s Health and Rehabilitation Centre in St. John’s.

worried about weight

Shockingly, children as young as nine are already dieting. Gail McVey, a Hospital for Sick Children research scientist and director of the Ontario Community Outreach Program for Eating Disorders, says her research has shown that 30 percent of girls and 25 percent of boys ages 10″“14 are dieting to lose weight. But dieting often backfires, setting the stage for unhealthy eating behaviours and disordered eating, says McVey.

For boys, the issue isn’t always trying to slim down. More often, they’ll choose unhealthy practices to bulk up — including using anabolic steroid pills or injections (the testosterone-like effects produce muscle), consuming creatine supplements (designed for bodybuilders) and high-protein drinks. Creatine can affect kidney function, while high-protein drinks can also be hard on the kidneys “because they have to work harder to get rid of extra protein,” explains Dr. Sacks. Young boys may also be casually “working out” with their parents’ weights, but this can be dangerous “because bones aren’t fused yet, so they may not be strong enough to handle the weight,” says Dr. Sacks.

modelling, the un-supermodel way

Want to help your kids grow up without growing obsessed with every inch of their bodies?

• LOOK IN THE MIRROR — not at your thighs, but your attitude. “Children learn at very young ages from not only what we say but what we do. Our own actions and beliefs (intentional or not) regarding eating, body weight and shape can negatively influence the way children feel towards their own body,” explains Chapman.
• TALK ABOUT HOW BODY SHAPE CAN BE INHERITED. “One thing kids need to understand is that genetics is going to play a strong role in their shape and size,” says Dr. Sacks.
• DON’T HAVE FOOD FIGHTS. Don’t micromanage how your kids eat. Rigid rules only encourage restricted eating. “Allow a variety of food but let the child decide what and how much she’ll eat — respect the child’s hunger cues,” says McVey.
• BE ACTIVE TOGETHER. Encouraging active living promotes healthy weight and self-esteem. But it’s not enough to shuttle kids around from swim classes to soccer to gymnastics — you need to participate. So try a game of catch, soccer in the park, hiking, skating or start a snowball fight with your kids.
• WATCH YOUR LANGUAGE. Avoid statements, both positive or negative, regarding your appearance or the appearance of others regarding weight. “Don’t normalize or glamourize dieting or the
  thin ideal,” says Chapman. And banish words like “diet” and “fat” from your vocabulary.
• GET YOURSELF A CLUE. It helps if you understand what’s going on in your kid’s body, so you know what’s normal too. McVey recommends Your Child’s Weight: Helping Without Harming, Birth through Adolescence by Ellyn Satter (Kelcy Press).
• CONSULT AN EXPERT. “If changes in nutrition are required for medical reasons, parents should consult with a registered dietitian to ensure their child continues to meet nutrient needs for growth and development,” says Chapman.

Angela Pirisi is a health writer and mom who gets nervous when her five-year-old daughter alludes to wanting to look like a pop star.