Childhood obesity is a major problem. But now news has emerged that one city - Leeds - has been making some progress.
Figures presented to the European Congress on Obesity suggest Leeds has managed to reduce the number of children who are extremely overweight.
The data showed there had been a 6.4% fall in obesity rates over recent years.
How significant is this?
A fall of 6.4% may not seem much - but given obesity rates have remained stubbornly resistant to attempts to shift them, the efforts of Leeds are being widely praised.
The data - compiled from the official school measuring programme - showed 8.8% of four- to five-year-olds in the city were recorded as obese in the past five years. That compared with 9.4% from 2009 to 2013.
And that has been judged to be statistically significant by experts.
But what has been particularly impressive is the fact that the biggest falls have been seen among the most deprived areas.
Rates of obesity fell by nearly 9% in these neighbourhoods.
How has Leeds done it?
Those involved in the Leeds project point to the work done with pre-school children.
The city council developed a child-obesity strategy a decade ago that made this age group a key priority.
Staff who work with pre-school children, including children's centres workers and health visitors, were trained to promote healthy eating.
And parenting classes encouraged healthy snacking, eating as a family and the importance of cooking nutritious meals from scratch.
The council has taken other steps too. There has been a big focus on getting children active through dance, while there has been an active local campaign to encourage families to reduce their sugar intake.
What have parents been taught?
The work with parents has been done in partnership with a charity called Henry, which runs programmes across the country.
In Leeds parents have been offered eight-week courses.
Henry chief executive Kim Roberts says they focus on some key messages.
She says it is important to give children a choice. "Offer them a choice of peas or carrots and let them decide," she adds.
Parents are encouraged to set a good example by eating healthily too.
One of those who has benefited is Belinda Mould and her daughter.
The three-year-old used to only eat beans, sausages and mash potato, but now likes a range of fruits and vegetables from mangoes and strawberries to cucumber and sweetcorn.
"Her absolute favourite is broccoli. She can eat loads of it," Belinda says.
Should other areas copy Leeds?
While the progress has been impressive, Leeds has not seen a similar shift among older children.
The school measuring programme also involves those at the end of primary school - 10- and 11-year-olds.
And the obesity rates for this age group have remained stable.
What is also true is that other places have also seen some small chinks of light in the battle against the bulge.
Public Health England is working with areas including Luton, the London boroughs of Lewisham and Tower Hamlets and Stockton-on-Tees to see what can be learned.
They have all seen some progress in reducing obesity rates - whether it is with older or younger kids.
So what can we take from the experience of Leeds?
Oxford University's Prof Susan Jebb, who has helped analyse the figures, says the key thing is that they give hope.
"It is sometimes too easy to think nothing is working, this shows something can be done," she says.
"What we need to do now is understand exactly why Leeds has seen the progress it has and also to look at the experience of other areas.
"They could hold the key to tackling child obesity"