Several sponsors of the World Cup have been condemned for providing unhealthy messages to children watching the games.
The World Cancer Research Fund (WCRF) criticised McDonald's, Coca Cola and Budweiser, who are all backing the football competition.
Teresa Nightingale, general manager for WCRF, said: "It would be a great boost for public health around the world if FIFA could show real leadership on this issue by announcing that it will not consider companies that promote unhealthy products as sponsors or partners in future."
However, she added that the charity hoped that "the World Cup will spark an interest in sport that will lead to a long-term increase in their [children's] physical activity levels".
Excess body fat, which can result from eating and drinking the wrong things, has been proven to increase the risk of developing certain types of cancer, including prostate, breast, bowel and pancreas cancers.