Children as young as six-months are being given inappropriate foodstuffs such as crisps, chocolate pudding and soft drinks, according to Dr Mary Flynn of the Food Safety Authority of Ireland.
Dr Flynn was speaking at a seminar for health professionals to publicise the authority's latest scientific advice and recommendations on infant feeding in Ireland.
She said Ireland has the lowest breastfeeding rate in Europe and the majority of babies are being weaned onto solid food too early.
Dr Flynn also said that some health problems that affect many adults may be partly due to their mother's diet while pregnant and what they were fed as babies.
The report and the guidelines are called "Best Practice for Infant Feeding in Ireland".
Speaking on RTÉ's News at One, Dr Flynn said that parents who feed their children these types of foods may not be aware that a baby's digestive system is still developing and cannot handle them.
"We now know that the timing and types of foods introduced in that first year of life can impact on lifelong risk of hypertension, heart disease, celiac disease and even diabetes," she said.
She said she believed the solution lay in treating infant feeding, not as a mother's problem, but as a family and societal issue.
Regarding the low rate of breast-feeding in Ireland, she said: "You know yourself that you go out to buy a card for a baby, it's got a bottle on it. Everything seems to suggest that the way to feed babies is bottles, and it's not.
"Finland were in this situation about 15 years ago, and they have completely turned around and they've one of the highest rates of breast-feeding over the last few years."