Making sure children get all the right nutrients, and not too much junk, can be a struggle. Start by setting a good example and focusing on the big picture.

Three-year-old Charles Weaver will happily stuff a piece of freshly picked kale in his mouth and gobble down a side of mushrooms.

So mom Laura McGrath Weaver doesn’t fret over the fact that he isn’t a fan of eggplant or a raw vegetable salad. In the long run, he’s eating nutritiously—and that’s what counts. “I don’t want to force him to eat anything,” Weaver said. “I want him to have a healthy relationship with food.”

Like many young parents, Weaver and her husband, James, are trying to make sure their son has a healthy diet. And for many adults, it’s not the diet they grew up on.

The latest guidelines from the U.S. Department of Agriculture, detailed at choosemyplate.gov, say vegetables and a small amount of fruit should fill half of a typical child’s plate. A protein, such as meat or beans, plus whole grains should fill the other half.

But making sure a child is eating well involves much more than measurements on a plate, said Erica Domrose, a clinical dietitian in the Center for Healthy Weight & Nutrition at Nationwide Children’s Hospital. “The first thing parents need to do is to set a good example,” she said. “That’s a hard one. If you’re eating chips and you don’t want your kids to eat chips, you’re not setting them up for success.”

For parents whose diets don’t meet the current guidelines, Domrose suggests working to change unhealthy habits as a family. “Go to the grocery store and pick out a new vegetable together and try it together,” she said. “Then find recipes to try it with and cook it together.”

Then, eat together. “Present the meal and let the kid decide what and how much of the meal they want to eat,” she said. “If all they want to eat is the mac ‘n’ cheese and you’ve given them their portion, that’s all they get to eat. Wrap up the dinner plate, put it in the refrigerator and maybe they’ll eat it later. But don’t give in and give them more of their preferred food.”

Dr. Joseph Geskey, a former pediatrician who’s now vice president of medical affairs at OhioHealth Doctors Hospital, said parents shouldn’t hesitate to tell kids that they’re struggling to eat right. “Kids can appreciate that, and it’s appropriate to say, ‘We’re in this together.’ ”

Next, Domrose said, look at portion control. One portion, whether it’s fruit, cereal, pasta or meat, should only equal the size of the child’s hand.

Plate size also is important. “Over the years, our plates and bowls have gotten bigger, and then we want to fill the plate up,” Domrose said. She said children should eat off of a 7-inch plate and adults should stick to 9 inches, which is about the size of a standard disposable plate.

What to Put on the Plate

Children who eat plenty of fruits and vegetables, drink milk and eat protein should be getting the vitamins and minerals they need, but the U.S. Centers for Disease Control and Prevention recommends that parents pay particular attention to Vitamin D, found in cows’ milk and eggs, and iron, found in red meat, poultry, eggs, beans and dark green leafy vegetables.

Still, Geskey said, eating specific foods isn’t as important as eating a balance of foods. If a child likes peas but not broccoli, feed her peas, he said.

A hot topic in children’s nutrition lately is sugar—both natural and added. While Domrose and Geskey suggest limiting the amount of sugar children consume, neither suggests eliminating it altogether. “We don’t want that dogmatic approach to nutrition,” Geskey said. He said no more than 10 percent of a child’s daily calories should come from sugar—and that includes the sugar in fruit. One cup of apple juice, for example, has about six teaspoons of sugar.

Some doctors recommend not serving fruit juice to children, but Geskey believes that’s going overboard. It’s fine, he said, as long as they drink it in moderation. Water and low-fat milk are usually better choices, Domrose said.

Weaver, of Clintonville, has shielded her son from processed sugar, but allowed him to eat his first chocolate cupcake on his third birthday. “I want him eventually to say, ‘I can eat one cookie, and I don’t need a whole sleeve of Oreos.’ ”

Dining Out

Restaurants present another challenge. “Try to choose healthy alternatives, such as grilled options instead of fried,” Domrose said. At fast-food spots, that’s especially important, she said.

In May, the U.S. Food and Drug Administration began requiring chain restaurants to post calorie counts on their menus, a useful tool for parents who want a sensible option. “Often they can find a low-calorie side with a meal,” Domrose said.

But some parents, like Morgan Bennett and her husband, Anthony, aren’t concentrating on calories. The couple, who live in Eastmoor, take their four children, all under the age of 7, out to eat about once a week. “I don’t look at the calories,” Bennett said. Instead, she chooses healthy options, usually from the adult menu, that include a lot of vegetables.

Overall, she takes a long view on what her children eat. “The advice I try to follow is what someone told me: Look at what your kids eat in a week, not in a meal or a day,” she said. “And always remember that in any recipe you can always double the vegetables. Always.”