The Consumers Association of Ireland and the Children's Rights Alliance have made a joint call for a ban on junk food advertising on television before the 9pm watershed.
In a statement issued to mark World Consumer Day today, they say a ban is needed to help reduce levels of child obesity.
The two groups have also called on the Government to take a leading role in lobbying the World Health Organisation to introduce an international code on the marketing of unhealthy foods to children.
Some 350,000 children are overweight or obese on the island of Ireland, the statement points out, and this figure is rising by 11,000 each year.
It blames the trend on unhealthy diets, which are also a major cause of heart disease, diabetes and some cancers.
The consumers association and the children's alliance say the media is one of the most important vehicles influencing consumer food choices and therefore one of the key solutions to the problem is to restrict the advertising of unhealthy foods.
The have called on the Broadcasting Commission of Ireland, which is currently reviewing its children's advertising code, to put the interests and health of children ahead of the profits of food companies by imposing restrictions on unhealthy food advertisements.
"Currently, processed foods, such as chocolate, crisps, fizzy drinks, sugary breakfast cereals and fast food, are the most heavily promoted and marketed products, even though dietary guidelines recommend that they should be eaten the least," according to the statement.
Dermott Jewell, chief executive of the consumers association, said: "Consumers must have a better knowledge of the nutritional content of the food they eat if they are to make informed choices.
"Broadcasters must acknowledge this right as a basic entitlement, especially to the young, and actively demand and ensure that their advertisers' code acknowledge it also."
Jillian van Turnhout, chief executive of the children's alliance, said the broadcasting commission needed to take a stand. "It's time to throw junk food advertising out with the rubbish."