If you're a parent, you've probably heard remarks like this during dinner: "I don't like milk! My toast is burnt! I hate vegetables! I took a bite already! What's for dessert?" It can be daunting trying to ensure a healthy diet for our children. So it's no wonder parents often resort to dinner time rules.

In our new poll, with the Robert Wood Johnson Foundation and the Harvard School of Public Health, 25 percent of families tell their children to eat everything on their plate, and 45 percent report setting restrictions on the types of foods eaten. Increasingly common are rules like "clean your plate," as well as newer strictures such as "no second helpings of potatoes," "no dessert until you eat your vegetables" and "sodas and chips only on special occasions."

This is all well-meant advice. But does it work? Kelly Brownell, who directs the Rudd Center for Food Policy & Obesity at Yale University, says, "No."

"By demanding that children eat things like vegetables before they have a dessert, it makes it seem like there's something wrong with eating vegetables, and that you have to swallow medicine before you get to the good part," Brownell says.

Not only that, but rules like this can backfire, according to Kristi King, a registered dietitian at Texas Children's Hospital and a spokesperson with the Academy of Nutrition and Dietetics. "Some of the studies have shown us that when they were put in a situation where somebody is saying 'finish this' or 'finish that,' the kids actually had more negative responses and actually consumed less of the food than the kids who didn't have that reinforcement of 'you need to finish.' "

The better option, King says, is creative negotiation. Take, for example, what she calls "Try It Tuesdays." On a "Try It Tuesday," parents, along with their children, pick out a new food to sample. It helps to involve the kids in preparing the dish as well, she says. This investment in the new food increases the likelihood that the child will try it and even enjoy it.

If they still say no, King suggests "no-thank-you bites" — something her friends made up for their 3-year-old daughter. It goes like this: The child just has to take a bite, and if she doesn't like it, she can say "no thank you," and that's that. But typically in this family, the "no thank you" turns into a "thank you," as the 3-year-old watches her parents eating and enjoying the food.

"You see her little hand reach across to the fork, and it kind of goes over into the vegetable," King says. "The next thing you know, you turn around and she's eaten the entire vegetable."

And, it turns out — as with most other behaviors — your kids are watching you, King says. "I had a parent who came into clinic not too long ago, and I said, 'OK, what's our goal for being here today?' And he looked at me and said, 'Make him eat vegetables!' And, my question back was, 'Well, do you eat vegetables?' And his answer was, 'No, I don't like them.' "

Dad mentioned he loved grilling, so King suggested he try that with vegetables. By their next visit, he'd become an avid veggie griller.

"Zucchini and squash and carrots and eggplants and onions and tomatoes — you name it, he was grilling it," says King. "[It's] a dietitian's dream — getting an entire family involved in eating more healthy foods."

As for dessert, Yale University's Brownell says there's nothing wrong with an occasional treat. "That doesn't mean that the only options are things high in sugar or fat or salt. There can be wonderful combinations of things like sorbet, sherbet, fruits — things like that can make outstanding desserts and be really good for people."

Some parents worry that having only healthy foods at home will lead kids to overdo it with junk food when they head off to college. But Brownell says there's no evidence to support this worry. And, in fact, the reverse is probably true.

Even if the young adults indulge in unhealthy foods at first, they're far more likely to return to the healthy foods they grew up with. "Having only good foods around the house makes all the sense in the world, and research supports this," he says.

So, Brownell says, fill your kitchen with healthy food, don't buy junk food, and watch what you eat. Your kids will follow your lead.

This story is part of the series On the Run: How Families Struggle to Eat Well and Exercise. The series is based on a poll from NPR, the Robert Wood Johnson Foundation and the Harvard School of Public Health. If you want to dive deeper, here's a summary of the poll findings, plus the topline data and charts.

Copyright NPR 2018.