Jamie Oliver has said there is no reason why David Cameron cannot do "the right thing" about a childhood obesity strategy.
The celebrity chef said the Government's decision on the matter will ultimately turn out to be the Prime Minister's legacy.
His comments come after the World Health Organisation (WHO) joined calls for a ''sugar tax'' on soft drinks, and as the Government prepares to issue a strategy for tackling obesity in the UK.
Mr Cameron has said he does not see the need for a sugar tax, although his position is believed to have shifted recently.
Speaking at the Andre Simon Food & Drink Book Awards where he was recognised for his contribution to the food industry, Oliver, 40, said the issue is not "rocket science".
He told the Press Association: "I honestly think that this childhood obesity strategy will set the tone of where we go in the next 100 years in public health.
"Regardless of who you vote for, it's Cameron's legacy. There's no real reason why he can't do the right thing."
He added: "Ultimately what he has to do is come up with a childhood obesity strategy that's relevant, logical and fitting for the epidemic that we're dealing with with regards to childhood obesity, but which is a metaphor for how creative and productive and excellent this country, is in the next 20 years."
He said he thinks people are getting tired of "miserable statistics" about childhood obesity decade after decade, asking: "How long can it go on?"
Oliver said he has the support of "every organisation around health give or take", adding: "The list is like 30 deep. Anyone that you would trust your kids with supports it."
He praised the Prime Minister's advisers, calling them "very impressive".
He said: "They have everything on the shelf. The question is - what's in the basket?"
Oliver said he expects an update in the next two weeks, but added that it might be pushed back.
"Everyone cares, but no one wants to take any pain. Everyone's got to take pain," he said, as he called on small businesses to do their bit, and praised efforts made by fast food chain McDonald's.
"Everyone always liked to poke at McDonald's. McDonald's has been doing more than most mid and small-sized businesses for the last 10 years. Fact. But no one wants to talk about it. And I don't work for them. I'm just saying they've been doing it - 100% organic milk, free range eggs, looking at their British and Irish beef."
He added: "My point is, everyone needs to do their bit. The corner shops need to do way, way more. We've got no standards for lunch boxes. The biggest enemy of school dinners is a lunch box.
"Teachers around the country are beside themselves, having to keep taking cans of Red Bull and Lucozade out of six, seven and eight-year-olds' lunch boxes. But there's no legislation that backs up a teacher to do such a thing. There's no standards," he said.
A third of 10 to 11-year-olds and over a fifth of four to five-year-olds in England are overweight or obese.
The award Oliver received at Thursday night's ceremony at The Goring Hotel in central London was the John Avery Award.
It was in recognition of his latest book, Everyday Super Food, and his contribution to the food industry over almost 20 years.