Jamie Oliver and Hugh Fearnley-Whittingstall have warned urgent action is needed to prevent a national health “catastrophe” caused by growing rates of obesity.
The celebrity chefs gave evidence to MPs today over the scale of the problem as they called for decisive measures to push consumers towards healthier choices.
Among the policies suggested by Oliver were a ban on TV junk food advertising to be extended to 9pm and an extension on a tax on sugary drinks.
He told ITV News that poor diets were a “massive problem” causing a triple blow of ill health, diet-related disease, and early mortality, which disproportionately fell on the poorest and most vulnerable.
His fellow chef and campaigner Mr Fearnley-Whittingstall said the UK faced a critical juncture as average rates of obesity steadily climb.
We can't miss this opportunity again. We're heading for a situation where 50% of us by the middle of the century will be obese. The NHS already buckling under the pressure of 25% of us being obese - imagine if that doubled.
Mr Oliver attacked Theresa May for her record personally, saying that plans for reforms created under David Cameron were "blown up” by Brexit and then pushed out by the current Government administration.
Blueprints for "what would have been the childhood first obesity strategy" created under Mr Cameron were whittled down to "a really sad version of what was going to be done", he said.
The chef is now pushing for "multi-pronged strategy" from the Government and businesses to tackle obesity levels, including setting targets on fats, salt and sugar in foods, rethinking the advertising of food, increasing knowledge about food, and making healthier choices cheaper and more accessible.
Rejecting suggesting that such actions would amount to a "nanny state" he said that many people were not getting the opportunity to make healthy choices.
He said: "If you go to a vending machine and there ain't choice, you ain't got a choice.
"If you go to a petrol station for your lunch for the third time that week and you ain't got a choice, you ain't got a choice. If you go to a supermarket in a poor area and everything that's on bogof (buy one get one free) is unhealthy and bad for you and there's no deals on the healthier things, you haven't got a choice.
"Even 50/50 would be fair. So even if there was legislation that says for every deal you do on junk food, there's one for fresh food, that would be fair. And we haven't even got that clarity yet."
He added: "Smoking took 40 years. We haven't got 40 years to do this. We will not have an NHS in 40 years' time if we don't get a hand around an environmental strategy that attacks ill health and protects child health."
However, Oliver said he remains "optimistic" that the Government will step up to the challenge.
In a message to the Prime Minister, he warned that politicians will be remembered for their actions - or lack of them - in the future.
"It has got so bad that it's now personal," he said.
"Any minister that doesn't do what they can to protect child health under their watch in the position of power they have will be remembered for this."
The Commons session comes ahead of the next chapter of the Government’s Childhood Obesity: A Plan For Action, which is expected later in 2018.
Other witnesses facing the committee include academics, health and fiscal experts, who will give their assessment of the Government’s performance in this area, and say what they expect from the next part of the plan.
Last week the Prime Minister described the UK’s plans to tackle childhood obesity as “ambitious” and “world-leading”, but she added that further action has not been ruled out “if the right results aren’t seen”.
Oliver has long been a campaigner for healthy eating, particularly when it comes to children.
His fellow chef has a new BBC series out, Britain’s Fat Fight With Hugh Fearnley-Whittingstall, looking at why people are eating so much.