Three-quarters of young dads are overweight or obese and more than a third are in denial about it, according to a new Australian survey.
In comparison, 57 per cent of women under 40 with families are overweight or obese and only 9 per cent wrongly believe themselves to be otherwise.
The survey by health insurer Bupa revealed 61 per cent of parents under 40 years were overweight based on their body mass index compared to 40 per cent of couples without kids and 45 per cent of young singles.
It also showed high numbers of Australians with children living at home suffered from tiredness, fatigue and headaches.
Alan Barclay from the Dietician Association of Australia said it was natural for people to become less active once they had children.
He said the index was a very crude instrument that didn't take into consideration body composition but it was often that ''bigger is better'' for men.
''I think men are bigger than women because we tend to carry more weight,'' Mr Barclay said.
''For women, it is more socially acceptable to be slimmer and there is more pressure on women than men to conform to this.''
Mr Barclay said the increase in obesity rates had led to a shift in social perspectives.
''Today, two-thirds of people are overweight or obese. If everybody is the same as you, you won't think you have a problem.''
Meanwhile, Bupa chief medical officer Paul Bates said differing behavioural patterns between the two sexes may have contributed to the statistics.
''While women and men both work, the model of a parent at home is a woman,'' Dr Bates said. ''My guess is women tend to be more practical regarding matters of health.''
Dr Bates said the gradual onset of chronic diseases masked the effects of obesity.
''We're one of the most overweight countries in the world,'' Dr Bates said. ''We do have a problem.''
Results from a recent study in the US suggested that parents' ability to lose weight was a significant contributor to their children's ability to avoid childhood obesity.
''Modern life is hard on everyone but especially if you have a family,'' Dr Bates said.
''We know that the health of both parents is important in setting examples for kids.''
Daniel Sjoberg, 37, from Fisher has a four-year-old daughter and a newborn son.
Mr Sjoberg tries to keep fit through bike riding, walking and chasing after his little girl.
''It can be a very hectic lifestyle. I think families find it hard to find the balance,'' he said.
''It can be a downwards spiral where the less active you are, the less likely you are to feel like doing exercise,'' he said.
He is using his two weeks of paternity leave to catch up on some exercise and look after his son.
''Sometimes the two [family and fitness] go together,'' Mr Sjoberg said.
''If you spend the time outdoors, it is a chance to keep fit.''
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