An Australian study suggests that parents of overweight school children can help their kids lose weight by doing a little studying of their own.

Parents of overweight children (ages 5 to 9) who took a six-month healthy lifestyle course saw their children's body mass index (BMI) drop by 10% in the next six months. Even better, the weight stayed off for another 18 months, through the end of the study.

Parents' behavior plays a large part in setting their children's food and exercise habits, especially in younger children, who may not even understand that eating more makes them heavier.

After taking the course, parents felt more comfortable saying "no" to their children's demands and setting limits on what type of food the children could eat, their TV and video game time and establishing consequences for breaking the rules.

It's parents who buy most of the household food, prepare meals and set the rules about what their children can eat. Parents' own food and exercise habits are constantly setting an example to their children. So parental behavior plays a large part in setting their children's food and exercise habits, especially in younger children, who may not even understand that eating more makes them heavier.

Many parents think that they're providing age-appropriate portions and healthy foods for their children when in reality, they're not.

In this study, parents of 169 moderately obese children, aged 5 to 9, enrolled in a six-month "healthy lifestyle" course. The course emphasized reading nutrition labels, understanding portion size, setting limits and being a good role model for the children.

Parents also assessed their own eating patterns and exercise behavior and set goals for change. After all, part of the program was to teach parents how to set a better example for their children.

Within six months, the children averaged a 10% loss in body mass index. There was also a noticeable drop in the children's waist size. When the researchers checked again, after 24 months, the weight remained off.

Half of the parents also took a parenting course along with the healthy lifestyle course. This had no effect on their children's weight.

The researchers believe that involving the parents more in their child's weight loss takes away some of the stigma from the child. It spreads the blame around, so to speak.

Children may not understand "A moment on the lips, a lifetime on the hips." Parents understand it all too well.

The study results were published in the February 2011 issue of Pediatrics.