SYDNEY: Fathers who play less of a role in child rearing are more likely to have overweight or obese offspring, Australian researchers said.

A study of almost 5,000 youngsters revealed that fathers who do not set clear limits for their kids are more likely to have heavier children, according to the Australian Associated Press.

Dads who did lay down boundaries generally had children with a lower body mass index, said the study by the Murdoch Children's Research Institute and The Royal Children's Hospital Melbourne.

Hospital specialist Melissa Wake said the study was the first to suggest that men could help prevent early childhood obesity.

The study found that a mother's parenting style had little impact on whether a child was overweight or obese. "Mothers are often blamed for their children's obesity, but this study suggests that for more effective prevention perhaps we should focus on the whole family," Wake said.

The study found that 40% of mothers and more than 60% of fathers polled were themselves overweight.

The research, to be presented at a pediatrics conference in Toronto this week, compared the BMIs of 4 and 5-year-olds with their how their parents behaved towards them.

Childhood obesity is growing in Australia, with more than 20% of preschool children either overweight or obese. The specialists said it was vital to study early parenting because home life often established patterns for life-long obesity.

Earlier research had shown that childhood obesity was highly stable during the primary school years, right from school entry, professor Wake said. "For instance, the BMI of a prepgrade child has an 85% correlation with their BMI three years later," she said.

"Obese school children are very likely to become obese adults." "Given the importance of the family unit in a child's preschool years, and its influence on their nutrition and physical activity levels, it is timely to look at the parenting roles of both parents and the impact they have on a child's tendency to be overweight or obese," she added. Extra weight is a precursor to serious childhood and adult diseases like asthma, diabetes, cardiovascular disease and cancer.

Parents play a big role in shaping children's eating habits. When parents eat a variety of foods that are low in fat and sugar and high in fiber, children learn to like these foods as well. Parents have an effect on children's physical activity habits as well. They can set a good example by going for a walk or bike ride after dinner instead of watching TV. Playing ball or jumping rope with your children shows them that being active is fun.