British lawmakers have asked the government to introduce a tax on sugary drinks and controls on price promotions for "unhealthy food and drink", in an effort to fight childhood obesity, Reuters reports.

The treatment for obesity costs the state-run health service 5.1 billion pounds ($7.65 billion) every year.

"One third of children leaving primary school are overweight or obese, and the most deprived children are twice as likely to be obese than the least deprived," said Sarah Wollaston, chairman of the Health Committee.

"A full package of bold measures is required and should be implemented as soon as possible."

Parliament's Health Committee said there was "clear evidence that measures to improve the food environment" must be used to deal with obesity.

In the report that it submitted to the government, the health committee said there should be strict controls on price promotions of unhealthy food and drink and a tax on full sugar drinks. The committee added that the proceeds should be used to help children at greatest risk of obesity.

It also said that the government should implement tougher controls on the marketing and advertising of unhealthy food and drink and that food labels should show also sugar content in teaspoons.

However, the drinks industry criticized the report's findings, saying the lawmakers had "swallowed" the agenda of lobbyists.

"No one seems to have considered hard-pressed consumers in all this," he said in a statement, adding that consumers pay billions in taxes on food and drink.