Leaders of 70 health organisations have signed an open letter expressing ?profound concern? about rumoured reversals to obesity policies.

The letter from the Obesity Health Alliance, signed by organisations including the British Medical Association (BMA), British Heart Foundation and Cancer Research UK, urges Prime Minister Liz Truss to ?reconsider any plans to weaken the public health measures? to tackle junk food.

The letter said cutting preventable illness caused by junk food would be crucial in tackling the NHS backlog, meeting the target to halve childhood obesity by 2030 and delivering on levelling up, as poor diet was a key driver of regional health inequalities.

The Government is reviewing its obesity strategy for England, including a ban on TV advertising of junk food before 9pm and multibuy deals.

It is thought the review is being carried out in light of the cost-of-living crisis.

Ms Truss is also on record as being against tighter rules.

In an interview with the Daily Mail, published in August, she said: ?Those taxes are over. Talking about whether or not somebody should buy a two-for-one offer? No. There is definitely enough of that.?

A survey by YouGov for Cancer Research UK this month found that 60% of people supported junk food restrictions being implemented in January as originally planned.

A recent Cancer Research UK report estimated that if trends continued, by 2040 more than 21 million UK adults would be obese ? a rise of more than six million on current figures.

In the Cancer Research UK poll, 56% of those in the most deprived areas, together with 63% of those in the least deprived areas, said they did not want to see delays to the implementation of a 9pm watershed on junk food advertising, as well as a ban on paid-for online junk food advertising.

Dr David Strain, chairman of the BMA?s Board of Science, said: ?It?s deeply disappointing to see the new Government threaten to throw away the progress we have made tackling obesity without any evidence it would do anything to help alleviate the impact of the cost-of-living crisis.