As well as marking the demise of the animated Kellogg characters Tony the Tiger and Snap, Crackle and Pop, which are used to advertise Frosties and Rice Krispies respectively, it could also mark an end to TV companies licensing their own cartoon TV characters to advertisers.
Childrens channels such as The Cartoon Network and Nickelodeon license their on-screen characters and have created ad-funded cartoon content that would now be forbidden if the proposals come into effect.
Ofcom also looked at the effect that celebrity endorsement, such as Gary Lineker for Walkers and Beyonce Knowles and Christina Aguilera for Pepsi, have on ads targeted at children. It noted that children responded positively to such ads and they could also be restricted.
The proposals are part of a study looking at ways to tackle the obesity crisis by demanding changes to ads that promote foods that are high in fat, sugar and salt (HFSS).
MPs on the Commons health select committee had asked for a voluntary withdrawal from TV advertising by HFSS advertisers.
However, Stephen Carter, Ofcom's chief executive, said a ban would be "neither proportionate nor, in isolation, effective".
Without the £523 million of food ad revenue, the Ofcom report also noted that a ban would undermine investment in children's programming on commercial television, reducing choice for viewers.
Elsewhere in the report, compiled in consultation with parents, children and nutritionists as well as the Food Standards Agency, Ofcom suggests that restrictions are imposed on the number of ads featuring foods that appear in ad breaks targeting children.
Ofcom's research showed TV advertising has a modest direct effect on children's food consumption. However, the significance of this is small when compared with other factors potentially linked to childhood obesity, such as exercise, trends in family eating habits, parents' demographics and school policy.
"I am encouraged that Ofcom has taken an holistic approach to the problem of child obesity, but we are aware that with the views of the Department of Health, the Foods Standards Agency and parents, there may still be some recommendations," Paul Curtis, the managing director of Viacom Brand Solutions, said. VBS is the sales house for Nickelodeon.
The Government will have the final say on whether to impose a ban on HFSS ads when the white paper is published in the autumn. Tessa Jowell, the culture secretary, said she'd prefer the food industry to produce a voluntary code.