Britain's obesity levels are the second worst in Europe, with only Hungary faring worse, latest figures show.
The report states: "Childhood obesity is at crisis level in many countries and poses an urgent and serious challenge. The increasing rates of childhood obesity cannot be ignored and governments need to accept the responsibility to address this issue, on behalf of the children they are ethically bound to protect.
"A failure to act will have medical, social and economic consequences of major magnitude. "
Prime Minister David Cameron has previously said he does not see the need for a sugar tax, but in recent weeks there have been suggestions of a shift in his position, with statements saying that a tax has not been ruled out.
Source: www.telegraph.co.uk