Fewer than one in three women are aware food eaten while pregnant and by babies under two can play a role in the development of obesity, type-2 diabetes and food allergies.
Research released on Wednesday reveals most 18- to 44-year-old women did not understand the importance of early life nutrition.
Neonatologist John Sinn said the 1000-day period from pre-conception to the first three years of life could have a significant impact on a person's health as an adult.
Just 29 per cent of women were aware that the food eaten while pregnant and by babies in their first two years of life could be a significant contributing factor to the development of obesity, type-2 diabetes and food allergies, the survey of more than 1000 women found.
The most common advice given to pregnant women involved reducing the risk of harm to their unborn baby by avoiding such things as alcohol, smoking, drugs, raw seafood and soft cheeses.
Most mothers surveyed said they diligently followed this guidance.
But advice on ways to improve the long-term health of the child was far less common – provided in only 6 per cent of pregnancies – although more than half of the pregnant women surveyed said they would like to receive more information such as this, according to the Galaxy survey commissioned by Danone Nutricia Early Life Nutrition.
Rommillia Emanuel, who gave birth to daughter Holly Kerney last week, said a healthy diet during pregnancy and breastfeeding was important to her.
"I made sure I didn't eat things I wasn't supposed to," she said. "I feel it's what you have to do – you eat healthy so baby can be healthy."
Mother-of-two Joanne O'Dwyer said she ate a fairly normal diet during pregnancy but avoided harmful things such as drinking. She said she spoke to her GP about her children's diets.
"Having a nearly three-year-old, they can be a bit fussy, so I am trying to get as much good stuff into them as possible," she said.
Midwife and lactation consultant Penny Maher, assistant director of nursing and midwifery at Centenary Hospital for Women and Children, said good nutrition during breastfeeding was extremely important.
"It's especially important that mums look after themselves and eat a healthy and varied diet," she said.
"It's important for not only the development of a healthy baby but that they eat well for themselves so they retain a healthy body mass index."
Ms Maher said maternal and child health nurses played a crucial role in providing information to new mothers.
She said a new clinic for women who have a high body mass index had just opened at the hospital.
"We provide them with access to a nutritionist to give them specific dietary assistance with keeping healthy and maintaining and managing their weight," she said.
Associate Professor Sinn said a healthy diet during pregnancy and during a baby's early years was important for a child's long-term health outcomes.
Ms Maher said it was important for women to have access to information about good nutrition.
"I think there's so much emphasis on weight control that good nutrition around times when women need to look after themselves, there's not the same impetus there and it would be excellent if there was a lot more that's directed to women and having babies and managing their diet when they're breastfeeding and feeding toddlers as well," she said.
She said it was also important for parents to be good role models for their children when it came to healthy eating – not only in terms of food but also eating times and meal sizes.