The Director of Human Health and Nutrition with Safefood says snacks and treats and have become everyday staples for children.
New research from the food safety and nutrition body suggests that foods like biscuits, crisps, chocolate and sweets are the second-most consumed food group by children.
Almost 25% of all meals now include food and drinks high in fat, salt and sugar (HFSS) that are not recommended as part of a healthy diet.
The research also found that 29% of children's afternoon and evening snacks are foods high in fat, sugar and salt.
Speaking to RTÉ’s Morning Ireland, Dr Cliodhna Foley-Nolan said that the food pyramid has been turned on its head.
She said that families generally start the day relatively well but bad food sneaks in as the day progresses.
"We've become confused between snacks and treats. So what we would have considered in the past to be special treats - the bars and the crisps - are now everyday staples."
One in three parents said they found it hard to cut back on the treat foods.
Dr Foley-Nolan said that treats are fine, if they are just treats.
She urged parents to talk to their children about what they eat and lead by example.