Class divide for chips, but not biscuits
Young children in poorer families are six times more likely to eat chips twice a day than their better-off friends.
However, when it comes to high calorie treats like biscuits, there is little class divide.
The diets of youngsters aged seven to eight years old, whose health and wellbeing is being tracked, show 12pc of children in households where a mother left school with just the Junior Cert had consumed chips more than once the previous day.
This compared to 2pc of families where a mother had a university degree, the findings from the latest 'Growing Up in Ireland' survey shows.
When it comes to biscuits, however, 21pc of the least affluent homes ate the sweet treats more than twice the previous day - but the sugary snacks were equally popular in 19pc of the wealthier homes.
A gap also emerged in the consumption of fruit more than twice a day.
Some 62pc of the poorer children had at least two pieces of fruit a day, compared to 76pc of the more financially comfortable.
The report from the ESRI points out that good nutrition at this stage is essential for health and development.
It sets down good eating habits for the future.
The survey found overall that 15pc of these children are overweight and another 5pc are obese.
However, when broken down by family income it emerged that 20pc of children from poorer backgrounds are overweight and 7pc obese.
Substantial numbers of children from high-income homes are also overweight at 13pc, but just 3pc were obese.
One-in-10 children who were normal weight at three were overweight or obese at when they reached seven or eight years of age.
But there is also hope for very young children who may be too heavy.
Some 13pc of three year olds who were overweight at age three had a normal weight when they were older. The majority of seven to eight year olds in Ireland are in good health.