Many kids are picky eaters when they are young. Some children are eager eaters who may still be picky, but who enjoy food and eating, and who may also find it hard to know when to stop.

While no one has unlocked all the reasons behind the increase in childhood obesity, Norwegian researchers believe that one key is helping children develop a healthy relationship with food.

Forcing kids to eat everything on their plate can have just the opposite effect — it asks them to ignore their own satiety signals and eat to please mom and dad.

The team looked at physical activity, television time and appetite traits to see which seemed most closely related to children's increase in body mass index (BMI).

Physical activity and the amount of time spent in front of the TV did not explain why some children’s BMI increased more than others. How children responded to food and eating was more closely related to their weight.

Parents were asked: Does your child look forward to mealtimes? Does your child show much concern about food? Does your child ask for more food even if they are full? Does your child eat faster than other kids? Does your child use food as a source of comfort?

The sight and smell of food triggers eating behavior for some children more than hunger does, they found. Children who have this sort of enthusiastic response to food are more likely to continue to eat even when they are no longer full. They also tend to eat more.

“…[T]he BMI of children who are particularly triggered by food increases more when compared with others. But we also found the opposite effect: a high BMI leads to children becoming even more triggered by food over time (at around 6 to 8 years old). As they get older, they are even less able to stop eating when they're full,” researcher Silje Steinsbekk of Norwegian University of Science and Technology’s Department of Psychology said in a statement.

This is where parents can really make a difference. Children need their parents to help them learn to regulate their own food intake. It's important to understand your child's eating habits. Limiting servings and the size of portions is one way to teach children to pay attention to their own satiety signals. Forcing kids to eat everything on their plate can have just the opposite effect — it asks them to ignore their own satiety signals and eat to please mom and dad. It’s a fine line that parents have to walk, but one that can eventually lead a child to a healthy relationship with food.

The study is published in the Journal of Pediatric Psychology.