Children need to eat less and move more to beat the obesity epidemic sweeping the island of Ireland, medics have warned.
Parents have been called on to make practical changes to everyday lifestyle habits like giving youngsters smaller portion sizes and fewer treats and fizzy drinks.
Safefood said less time in front of the television, 60 minutes a day physical activity and getting a good night's sleep will also make Ireland's children more healthy in the future.
Research shows approximately one in four primary school children are overweight or obese, with 6% of three-year-olds classed as being obese.
Lynn Ni Bhaoigheallain, chair of the safefood advisory board, said: "We all want children to have a bright future and we get them into all sorts of healthy habits, like brushing their teeth or crossing the road safely.
"This campaign is about supporting parents in making small changes in their everyday family lives."
The cross border campaign to help parents take on childhood obesity features television, radio, poster and point of sale advertising and includes a free booklet.
Launched by safefood - in partnership with the Republic's Health Service Executive and Healthy Ireland Framework, and the Fitter Futures for All Implementation Plan in Northern Ireland - it also reminds parents about the negative health impacts of excess weight in childhood and how this can impact on a child's quality of life.
Consultant Paediatrician Dr Sinead Murphy also warned obese children face serious illnesses in adulthood.
"With a quarter of children overweight or obese, we need to tackle the issue of childhood obesity head on or our next generation will be beset with significant health problems later in life," said Dr Murphy, Clinical Lead for the W82GO Healthy Lifestyles programme at Temple Street Children's Hospital in Dublin.
"Evidence shows that once obesity is established, it is both difficult to reverse and can track into adulthood.
"Sadly, children who are overweight are at serious risk of becoming adults who are obese.
"This increases the risk manifold of developing serious illnesses such as type 2 diabetes, heart disease, stroke, certain types of cancers and shortened life-expectancy."
Getting parents to replace fizzy drinks, juice drinks and cordials with water, and being realistic about foods that 'should be' treat foods, are key targets in the campaign.
Dr James Reilly, Health Minister in the Republic, added: "Obesity presents a real clinical, social and financial challenge which will have a detrimental legacy lasting decades and which will undoubtedly lead Ireland to an unhealthy and extremely costly, if not unaffordable, future if action is not taken now.
"I want to encourage everybody to help create generations of healthy children who can enjoy their lives to the full and reach their full potential as they develop into adults by making healthier food choices, by being more active and taking the first steps towards reducing overweight and obesity."
Elsewhere Dr Tracy Owen, consultant in public health medicine at the Public Health Agency (PHA), maintained the new campaign will complement the wider work that is being undertaken in Northern Ireland to prevent obesity and the PHA's Choose to Live Better campaign.
"We know that around one in five Year 1 children in Northern Ireland are overweight or obese," she said.
"Combined with physical activity, the best way to avoid this problem is to ensure that children eat food which gives them sustained energy but is not loaded with fat and sugar.
"Once we become obese or overweight, this can be difficult to reverse and ensuring children have healthier eating habits will benefit them for years to come."
Professor Ian Young, director of the Centre for Public Health, Queens University Belfast, said obesity in children is an increasing problem with major public health consequences for now and the future.
"It's very important that we encourage more active lifestyles and better diets in children and their families and this campaign will play an important role in achieving these goals," he said.