A "sugar tax" should be introduced by the UK government to help curb obesity in childhood, a campaign group says.
Action on Sugar has produced a seven-point plan to discourage children from consuming foods and soft drinks with high levels of added sugar.
The group wants measures brought in to cut added sugar in food by 40% by 2020, to cut fat in foods and to ban sports sponsorship by "junk food" companies.
The Department of Health has said it will consider the recommendations.
Action on Sugar is a group of specialists concerned with sugar and its effects on health. It says one in five 10 to 11-year-olds in the UK are now obese, while one in three are overweight.
The group has produced an action plan for the government following a request for its views from Health Secretary Jeremy Hunt.
The seven proposed measures are:
- Reduce added sugars in food by 40% by 2020
- Ban all forms of targeted marketing of ultra-processed, unhealthy foods and drinks to children
- Disassociate physical activity with obesity by banning junk food sports sponsorships
- Reduce fat by 15% in ultra-processed foods by 2020
- Limit the availability of ultra-processed foods and sweetened soft drinks as well as reducing portion sizes
- Introduce a sugar tax to incentivise healthier food
The group's chairman, Prof Graham MacGregor, said current policies were not working and that obesity could be prevented if "the food environment is changed".
"The UK requires the implementation of this coherent strategy, starting by setting incremental sugar reduction targets for soft drinks this summer. No delays, no excuses," Prof MacGregor said.
Dr Aseem Malhotra, cardiologist and science director of Action on Sugar, said it was "really quite shameful that the food industry continues to spend billions in junk food advertising targeting children".
"It's time to bust the myth of physical activity and obesity and dissociate junk food and sport," he added.
A Department of Health spokesman said: "We know some people eat too many calories including sugar. Childhood obesity is at its lowest since 1998 but more should be done.
"Next week we will get expert scientific advice on sugar which will help shape future thinking. We will consider these recommendations as part of this."
Earlier this year Dame Sally Davies, the chief medical officer for England, said a sugar tax may have to be introduced to curb obesity rates.
She told a committee of MPs that she believed "research will find sugar is addictive", and that "we may need to introduce a sugar tax".