A Walkers crisps leaflet featuring ex-footballer Gary Lineker has fallen foul of the Advertising Standards Authority, with two complaints upheld.
Gary Lineker makes millions advertising Walkers crisps
The ASA agreed Walkers wrongly implied most standard packs of its crisps had 8% or less of the recommended daily amount of salt, when 12 types had more.
And the leaflet did not consider children's recommended levels, it said.
Walkers said these complaints, made by campaign group Consensus Action on Salt and Health (Cash), were "minor".
Cash also complained about Walkers' claim that a bag of its crisps contained less salt than average slice of white bread.
However, this complaint was dismissed by the ASA.
In the UK adults are recommended to consume no more than 6g of salt a day.
High levels of salt consumption have been linked to a range of health problems, including high blood pressure and heart disease.
Cash said the leaflet implied that all 34.5g packs of Walkers crisps, except for salt and vinegar and pickled onion flavours, contained 8% or less of this recommended amount.
In fact, the claim was only true for 21 out of 33 types of Walkers brand crisps.
Cash also said the leaflet failed to highlight the fact that children under the age of 11 are recommended to eat less salt than adults.
In fact, a standard bag of Walkers crisps contains 25% of the maximum daily recommendation of salt for a three-year-old.
Children aged one to three are recommended to eat no more than 2g of salt a day. The figure for four to six-year-olds is 3g, and for seven to ten-year-olds 5g.
Professor Graham MacGregor, chairman of Cash and an expert in cardiovascular medicine at St George's University of London, accepted that Walkers had cut the amount of salt in some of its brands.
But he said the company had been wrong to imply that every crisp was now better for you.
He said: "To imply that a Walkers Sensations Walkers Oven Roasted Chicken with Lemon & Thyme Flavour crisp is 'better for you' when it contains approximately one and a half times the salt level of seawater is in my view socially irresponsible.
"Pepsico International, Walkers' parent company, is one of the biggest drink and snack companies in the world, and in my opinion they should behave more ethically."
Walkers said the two complaints which had been upheld were "minor".
Neil Campbell, general manager for Walkers, said: "We reduced the saturated fat of Walkers crisps by 70% and the salt content by 25% earlier this year and felt that it was important to communicate these changes to enable people to make informed choices about our products.
"Our intention was always to communicate this in a clear, open and meaningful way."