Leading specialist Dr Nadim Haboubi, chairman of National Obesity Forum Wales, bemoans young children not being involved in activities.
"Children have computer games, iPads and they sit there for hours," he told BBC Wales.
"Unlike perhaps when we were children, there's also a genuine fear it's unsafe for young children to be outside playing, unsupervised.
"They eat too much junk food and now in the school holidays you can see them in burger restaurants from the morning onwards - the places are packed.
"I drive from home to work and there are seven 24-hour burger restaurants but no leisure centres open until late."
"Sweets used to be something you had at Christmas or special occasions, now they're given out as rewards.
"You've got to detect problems at an early age, so it's down to the parents. Obesity can keeping getting worse like a cancer unless you manage it.
"But for those in deprived areas, healthy food is not very affordable either for a lot of people."
Obesity levels are significantly higher than average in Merthyr, Caerphilly and Rhondda Cynon Taf, and significantly lower in Monmouthshire, Conwy and the Vale of Glamorgan.

Opinions on Childhood Obesity

Linda Bailey:

• "Even though nearly three quarters of children have a healthy weight, this year’s findings once again highlight the stark difference in child growth depending on where children live. We know there are higher rates of overweight and obese children living in our poorer communities." (28.5 per cent of children living in the most deprived areas of Wales were overweight or obese compared to 22.2 per cent in the least deprived areas.)

Dr. Tracey Cooper - Chief Executive of Public Health Wales:

• "We are grateful to all the families that allowed their children to take part in this valuable piece of work."
• "We have much to do to tackle the high rates of children above a healthy weight in Wales, especially in our most deprived communities.
• "We will team up with partners across Wales to work more closely with families and communities to improve people’s health where they live, learn, work and play.
• "We will do more to focus on improving health and wellbeing in the early years, where we know we can have the biggest impact."