I don't know about your place, but summer holidays around here are a time to get a little bit loose. We head to the beach, we eat ice creams, and we lie around watching movies when it's too hot to venture outside.
And let's face it, we're all allowing a bit of extra screen time, so we can just get stuff done around the place without the need to entertain the children 24/7.
Not a problem if you do it occasionally, but our kids are on holidays for six to eight weeks over the summer – is that long enough to undo all their great health and fitness work throughout the year?
With one in four children being overweight or obese, the University of South Australia thinks the situation is serious enough to conduct a study in children's diets and the way they spend their time over the summer holidays.
The study, funded by the National Health and Medical Research Council, will track the behaviour of over 300 grade four students over three years, assessing their diet, time use and activity – as well as their fitness and body fat percentages.
Professor Tim Olds, one of the study's authors, says it's important to understand the root of the problem, which is still elusive despite significant time and money being invested in trying to solve the problem.
"We haven't seen any reduction in childhood overweight and obesity, despite hundreds of studies and tens of millions of dollars", he says.
"What we know about overweight and obese children is that they are more likely to stay this way into adulthood, making them more likely to be at risk of diabetes and cardiovascular diseases at a younger age."
Olds says it's too early to tell how much damage is done over the summer break in Australia, but evidence from overseas suggests we should be concerned.
"Strong evidence in the US and Europe shows that the entire increase in children's fatness – and decrease in fitness – occurs during the summer holidays, but in Australia, we don't yet have this data.
"We do know, however, that Australian kids use their time very differently on holidays which, when coupled with diet, may be associated with increased weight gain and reduced fitness."
Olds says what we do know is that children are more sedentary during the holidays.
"Each day on holidays kids get almost an hour's more screen time, 40 minutes' more sleep, and about 15 minutes less physical activity compared to term time," he says.
It's not just the extra-curricular sports that take a break over the long holidays, it's also just the incidental day-to-day activities too.
"Clearly, when kids are at school, their time is highly-structured – they have set times for PE (physical education) and opportunities to exercise – plus, and their calorie intake is mostly limited to what they have in their lunchbox," Olds says.
"On holidays, the days are much more unstructured, with a lot of free time to watch TV, play video games and raid the pantry – all sedentary behaviours that can increase the risk of weight gain and reduced fitness."
All of which makes sense. Don't we all raid the pantry and watch TV more when we've got all day at home and nothing much to do?
But it's the question of whether those endless summer days are enough to undo an entire school year's worth of activity and healthy eating that this study is trying to get to the bottom of.
"If we can find links between children's fitness and fatness on summer holidays, we can start to think differently about interventions such as structured holiday programs and camps, as well as family-based interventions, that can boost children's physical activity over summer," Olds says, who adds that obesity is damaging to health but largely preventable.
"This study will be the first in Australia to examine both children's eating habits and their use of time over the summer holidays, so that we can find effective ways to address the very serious issue of childhood obesity."