They will conduct the world-first study - Healthy Dads, Healthy Kids - funded by the Hunter Medical Research Institute.
The six-month study has shown that kids mimic their fathers over their mothers when it comes to healthy eating and exercise.
Associate Professor Philip Morgan, who heads the new program, saw surprising results in a previous trial involving 165 overweight children.
He found kids who lost the most weight had fathers who were engaged in the new eating and exercise plan.
In another trial, involving 65 men in an online weight loss program, he found that the children of men involved - and even their wives - also shed kilos.
"Mum can purchase and prepare the food but dads will often have less greens, or just meat and potato. The kids think 'mum makes me eat this' and she is painted as the bad guy," News.com.au quoted Morgan, as saying.
"Fathers influence the food and physical activity habits in the home through their behaviours, attitudes and approach to food and eating, and act as a role model to their children," he added.
Morgan said that mothers, as primary care givers, were easier to inform but when fathers make changes the whole family becomes healthier.
"We have seen striking results. These dads are still allowed to have a beer and enjoy things in moderation. It was subtle changes to their nutritional habits that made the difference. They see their lives change, they sleep better, and have much more fun together," he said.