Campaigners for children's health have launched a "super-complaint" against online marketing of junk food to children.
The Children's Food Campaign (CFC) handed over complaints against 54 products to the Advertising Standards Authority (ASA).
The group targeted companies that advertise products with high sugar, fat and salt levels using websites that appear targeted towards children.
Products targeted included Rice Krispies, Coca Cola, Butterkist Toffe Popcorn, Crunchies, Pringles and Orios.
Malcolm Clark, spokesman for the CFC, said the complaints highligghted the use of animations, interactive games promotions and videos to push the products on a young audience.
"The internet is a different space to television, when the broadcasting codes mean that these sorts of products can not be advertised during children's programming," he said.
"However that is just not the case with the internet, meaning children can easily be targetted at any time, while parents are not aware of what they are seeing.
"We have an epidemic of obesity amongst children and although changing one facet will not solve the problem, it would be a strong step in the right direction.
"We want parents to have control and understanding of the way children are targeted so that they can make the most educated dietary choices."
The complaints follow a report published by the CFC along with the British heart Foundation in December 2011, titled The 20th Century Gingerbread House: How Companies are Marketing Junk food to Children Online, which examined around 100 companies' websites.
"This super-complaint targets those companies we have re-assessed and feel display the highest level of irresponsible marketing towards children."
The charity is calling for consistent advertising regulations across all media to protect children's health.
An ASA spokesman said: "The ASA will, as with all complaints, carefully and thoroughly assess the concerns put forward by the CFC."