Teaching your kids healthy eating all starts with trips to the supermarket. (Image) iStock

Here's how to toe the line without going overboard.

When it comes to children and food, parents these days face a tough conundrum. On the one hand, we're constantly being told that we're in the midst of an obesity epidemic but we also know that eating disorders are a real threat to young people.

So how can you help your children develop a healthy relationship with food so that they aren't tempted to over-do it and end up dangerously overweight or starve themselves to copy their favourite Instagrammer?

"Parents face a double-edged sword," Professor Susan Sawyer, director of the Royal Children's Hospital's Centre for Adolescent Health, told Coach.

"On one hand, you don't want kids growing up overweight but on the other hand you have to be very careful about the messages you give because you don't want to engender unhealthy relationships with food."

After 25 years working in children's health, Professor Sawyer has the following advice:

Remove guilt from food

One of the best things parents can do for their children is to avoid framing foods as something to feel guilty about.

Professor Sawyer suggests parents get used to referring to foods as "everyday" foods or "sometimes" foods so that children learn to understand that healthy foods should be eaten all of the time and high-fat or high-sugar are reserved for parties or special occasions.

"The sorts of foods we want kids to be eating every day are not fizzy drinks or chocolates and cakes," she explains.

"[But] in the context of an obesity epidemic, those sorts of foods shouldn't be framed as foods we should feel badly about eating. These foods [can] be special foods that you eat at parties or special celebrations."

By making sure your children follow a healthy diet from a young age, with treat foods as well, you'll give them the best chance of remaining slim.

"Adolescents typically want to start out eating in a more healthy way, typically because of dissatisfaction with their appearance," Professor Sawyer points out.

"A little bit of success then engenders a slippery slope to an increasing loss of weight."

Lead by example

You can yell at your kids to eat healthy all you like but if your pantry is stocked with biscuits, chips and chocolate that you eat regularly, then you're going to have a hard time getting your message across.

"If energy-rich foods aren't bought on a regular basis, it avoids the very debate that can occur at the end of a busy day," Professor Sawyer says.

"Children learn by doing and by observing."

The way parents talk about food and how often they engage in exercise can also have a significant influence over their children's health habits.

"It begins from birth – we learn whether food is framed as a reward for children being good or whether it's framed as there being 'good' foods and 'bad' foods rather than the notion of everyday foods and special foods," Professor Sawyer explains.

"Parents may need to ask, 'How physically active are we? What are the sort of activities we might do as families?' There are some tremendous opportunities that come from parents doing activities together with their kids."

RELATED: Here's why you shouldn't reward your toddler with food

Teach them to be social media savvy

As kids get older, their peers start to influence their feelings about food and their bodies, and these days social media gives young people a broader community to compare themselves to.

"Brain maturation in the adolescent years … gives them a pressing capacity to compare and contrast themselves to others, particularly in terms of physical appearance, social status and relative worth," Professor Sawyer explains.

"Young people become more motivated to look and act a particular way in order to fit in with that social group. [And] for young people growing up now, their comparative population is the world's 1.8 billion young people in the world."

Professor Sawyer says that social media is giving young people an "unattainable notion of perfection" to compare themselves to, and parents need to be ready to support them and help them understand the staging and editing of the imagery they are often exposed to.

"The role of parents has shifted to not just parenting in the home, but also to helping young people negotiate their engagement in social media," Professor Sawyer explains.

Keep conversation lines open

One of the easiest ways to keep tabs on your children's relationship with food and their bodies is to facilitate opportunities for relaxed chats about what is on their mind.

"Whether it's driving to sporting activities or walking the dog together ... spending time together to talk and cement relationships is a strategy to allow more complex conversations to happen when kids get older," Professor Sawyer says.