England's chief medical officer says she is considering recommending a tax on unhealthy food to buy more fresh fruit and vegetables.
Prof Dame Sally Davies has been asked to read more about what can be done to the government's target of halving childhood obesity by 2030.
Ideas include a tax on added sugar in baby food and on high-calorie food such as pizzas and cakes
The food industry has always said taxes would not change consumer behavior.
Lady Sally duty BBC News she was going to be "as bold as I can", while maintaining she was not "anti -fun ".
Following research linking ultra-processed foods ̵
And based on The tax on sugary drinks will be introduced in April 2018, the tax deduction can be used in other ways to help families live healthier lives.
"I want parents to be incentivised to buy healthy food, "she said. "We need to make sure that fresh fruit and vegetables are cheap.
" Maybe we have to subsidize them at charging more, by taxing unhealthy food.
"Parents are then nudged to buy the healthy version because it is cheaper."
But some plans still had to be worked out.
, "she said.
The Health Secretary, Matt Hancock, has commissioned Dame Sally to produce a report by September, with a series of recommendations for the government.
She said experts on nutrition, science and public health and representatives from the food and drink industry would all be asked to contribute their ideas.
When asked why another strategy on cutting childhood obesity was required, she said she regretted the process "taking so long"
"I should have chivvied harder to get us there faster, "she said.
But she said public consultations had to be done properly, and that took time.
" I, as an independent adviser, we wish we could do things faster, "Lady Sally said.