The Government's new anti-obesity strategy, announced on 23 January, opted not to extend rules that currently prohibit junk-food advertising around TV shows aimed at under-16s.
Instead, the Government has ordered the media watchdog to bring forward its planned review of rules concerning the advertising of foods that are high in fat, salt or sugar.
An Ofcom spokesperson said the review will look at whether the current scheduling restrictions are achieving their intended objectives.
She said: "It will also consider whether the restrictions are being implemented consistently across broadcasters and in the way intended, whether advertisers are complying with the letter and spirit of the rules and whether advertisers have increased their HFSS ads in adult time, but early enough for kids to see."
By July, the regulator will have six months of data concerning the impact of the ban on junk-food TV advertising to under-16s.