First-time mums are not eating enough fruit and vegetables, although breastfeeding mothers are slightly better nourished than those who don't breastfeed.

A Melbourne study of 529 new mothers found only 7 per cent met the recommended five serves of vegetables a day, while a bigger proportion - 58 per cent - ate two servings of fruit.

Deakin University researcher Deborah Leslie said breastfeeding mums consumed about an extra cup of cooked vegetables than non-breastfeeding mothers and ate a wider variety of fruit and vegetables.

She said it was concerning that overall, women were not consuming the recommended amounts.

Ms Leslie said mothers who ate a wide variety of healthy foods were more likely to have children who ate a varied diet, because babies are exposed to flavours in the womb and through breast milk.

"A mum who regularly eats a range of fruit and vegetables will be helping to improve her child's acceptance of those foods," she said.