How do you convince a child to choose better foods?

In a world that celebrates chicken nuggets, snack puffs and french fries, how do you convince a child to choose better foods like broccoli, fresh fish or apple slices?

If it feels like a losing battle, you're not alone. Raising a healthy eater is one of the biggest challenges parents face. And it's also one of the most important.

It's a common perception that children are young, healthy, active and thin, and bad food choices won't have a big effect. But the reality is that lifelong eating habits are being formed at an early age. And studies show that adult health problems like heart disease, diabetes and obesity begin in early childhood. Fatty streaks start forming on the aorta, and coronary arteries can show signs of damage in children younger than 10.

"It's such a challenge for parents," said Julie Mennella, a developmental psychobiologist who studies childhood taste preferences. "The food environment is so abundant with these nutrient poor foods. And we've got a brain that finds these tastes extremely palatable."

But parental concerns about the importance of healthy eating can sometimes backfire, causing children to reject foods or develop preferences for less healthy options. While you can't always control what your child eats, you can learn from the research and avoid what experts say are six common food mistakes.

Creating forbidden foods

Studies show that food restrictions backfire. When sweets and sodas are in the home and placed out of reach or restricted, it results in a "forbidden food" effect and just makes children want those foods more.

In a seminal study at Pennsylvania State University, children in day care were allowed to eat as many apple or peach cookie bars as they wanted. (In earlier taste tests, the kids had rated the cookies as "just okay" and certainly not binge-worthy.) Another batch of the fruit cookies was put in a clear jar on the table, and the children were told they could have those cookies later.

Although the children already had free access to similar cookies, they couldn't stop thinking about the cookies in the forbidden jar. When it was finally opened, they binged, eating three times as many cookies as they did when they were freely available.

The research is one of many studies to show the downside of restricting foods and trying to control what a child eats. Children raised in highly restrictive homes are more likely to be overweight and crave sweet and fatty foods.

The findings don't mean you should give children unlimited access to cookies and soda. Keep junk food out of the house and keep healthier snacks - apple slices, cheese and crackers or carrot sticks and ranch dressing - on hand. The goal should be for the parent to control the quality of the food in the house, and for a child to take it from there.

Keeping kids on a regular meal and snack schedule can help. "It's not laissez faire," said Isobel Contento, emerita professor of nutrition and education, Teachers College, Columbia University. "It should be on some kind of schedule. You can offer healthy food and sometimes not-so-healthy food. They get to choose what they eat."

Hiding vegetables in foods

Some cookbooks and parenting websites tout making macaroni and cheese with pureed butternut squash or hiding zucchini and beets in a brownie. It's fine to add healthful ingredients to foods, but it's not going to help a child learn to eat a more varied diet.

Feeding a child a squash brownie doesn't teach them to like squash - it just teaches them to like a brownie.

A better approach to teaching kids to eat more vegetables is to create "food bridges." If you know your child likes carrots, for instance, try introducing other orange foods like sweet potatoes or pumpkin. Mashed potatoes are a short food bridge to mashed cauliflower. If your child likes corn, add a few peas or carrots into the mix. Even if your child picks them out, it's still a way to introduce them to a new food.

Treating fat and thin children differently

Sometimes siblings in the same home can have different eating habits and body development. But the solution isn't to restrict the eating of the overweight child, pediatric obesity experts say. The household food rules for both children should be the same. (An exception might be if a child has diabetes or a food allergy.)

A thin child shouldn't have access to processed foods and soda just because they aren't overweight. Parents should set the example, and both children should have equal access to healthful food options. And it's okay for everyone in the family to have dessert or a birthday cupcake from time to time.

"The same foods that are healthy for one child are healthy for another child," said David Ludwig, professor at Harvard Medical School and co-director of obesity prevention at Boston Children's Hospital. "And what's going to treat a weight problem in a child with obesity will also help prevent the problem from developing in a sibling who is thin."

Not giving children input

Parents can control the quality of the food in the house, but children should still be part of the decision-making. Taking kids grocery shopping or to a farm stand allows them to pick the vegetables they want. (But be warned: Grocery stores often display junk food at a child's eye level.) Bring children into the kitchen to take part in food preparation. Sometimes you can cook vegetables together; sometimes dessert. If you have the room and time to garden, involving children in growing their own food has been shown to help with food acceptance.

Researchers at Teachers College studied nearly 600 children from kindergarten to sixth grade. Most of the children took nutrition classes, and some of the children were given cooking lessons. The children who learned to cook their own foods were later more likely to choose those foods from the school cafeteria.

"Including children with the food preparation is considered a good way to help them become familiar with a food and be willing to try it," said Contento, a co-author of the study.

Giving up

Studies show it can take 15 or more tries to get a child to like a new food, so it's a mistake to give up. While you can "gently" encourage a child to try a new food, don't force, cajole or offer a reward. (Some research suggests children start liking foods even less if they are bribed to eat them.)

And even if your child is a champion of picky eating, breakthroughs can still happen. If your child has a friend who is an adventurous eater, invite them over for dinner. Studies show that children can learn good and bad eating habits from friends. (But don't make a big deal about it.)

When your fussy preschoolers leaves the green beans on the plate, make an example of enjoying them yourself. And don't be afraid to make foods more tasty. If your child likes cheese, put cheese on the broccoli. Ranch dressing and peanut butter can be great dips for carrot and celery sticks.

"Most kids eventually do come to like the foods we eat," Contento said. "Try different ways of cooking the food, change how it's presented. I have great empathy for parents these days, but keep trying."

Forgetting to enjoy the family table

Don't let meals be a source of stress, and avoid food battles. As your children grow, they will remember more than just the food. Food traditions - a special ritual at Thanksgiving or popcorn night watching a movie - last in our memories and create positive associations with food.

"Food habits can define the family," said Mennella, a member of the Monell Chemical Senses Center in Philadelphia, a scientific institute focused on taste and smell. "It's not just about the foods you eat every night. It's the time to shape what you want your family to be. What are the special foods that define who you are as a family? It's looking at food in a different way, as an identity that bonds people and triggers memories of childhood."