Bruce Haines, group chief executive of Leo Burnett London, which holds accounts with McDonald's and Kellogg's, told a conference on food promotion that some campaigners and politicians were "politically opposed to any advertising".
Haines gave evidence on obesity to the Commons Health Select Committee last November. He said: "The session was not the most comfortable because the premise of innocent until proven guilty was reversed.
"Many on the committee displayed a distaste for advertising in general. This issue is giving advertising a bad name."
Haines said advertising was "a convenient target for politicians" but that banning advertising to children "wouldn't even begin to address the problem".
Haines said that advertising could instead "use its power to persuade people to embrace an active lifestyle".
