Babies widely starting on solids too early or too late

New research reveals nearly half of New Zealand babies are being introduced to food earlier or later than is recommended putting them at greater risk for ongoing health issues including obesity, anaemia and growth and developmental issues.

The research, published in the British Journal of Nutrition, looked at when babies in this country’s largest longitudinal study of child development, Growing Up in New Zealand, were first introduced to food outside of breast milk or baby formula.

The study found that 43.5 percent of the more than 6000 babies in the study were not introduced to foods at the age recommended by the Ministry of Health, with 40.2 percent introduced early and 3.2 percent late. 

The guidelines recommend that food starts being introduced to babies from around six months old, a developmental stage at which babies start to need a wider variety of nutrition sources for healthy growth and development.

University of Auckland researcher and co-author Professor Clare Wall said that while breastmilk or infant formula alone supply the nutritional needs of infants until the age of six months, beyond this age other foods are needed to attend to an infant’s nutritional and developmental needs.

“We know that nutrition in the first year of life not only impacts growth and development in that period, but also can influence longer-term health trajectories.”

“The early or late introduction of food is associated with a range of issues that can persist later into childhood” said Professor Wall.

She says research shows that babies who are introduced to food earlier than is recommended may be at increased risk of developing gastrointestinal infections, while impaired growth and development are related to late introduction, potentially due to shortage of vitamins and minerals such as iron, zinc and vitamin A.

Iron deficiency anaemia, and child obesity are related to both early and late food introduction. There is also an increased risk of food allergies if eggs, peanuts, cow’s milk, tree nuts, soy, sesame seeds, wheat, fish and shellfish are not introduced before 12 months of age.

The study looked at when food groups were introduced to babies and found that particular foods were more likely to be introduced outside of recommended guidelines.

Of concern, was that more than 45 percent of caregivers delayed the introduction of meat and alternatives which include nuts, eggs, tofu, beans and seafood, a finding that researchers say could mean babies are missing out on important sources of protein and iron. Previous studies have shown that around 14 percent of children in Auckland aged six – 23 months old are deficient in iron.

Also concerning was that one in 10 infants were introduced to fruit and vegetables after seven months of age.

Early introduction of solids was more prevalent among infants not breastfed for six months and late introduction of solids was more prevalent among infants breastfed for more than six months.

The study also found an association between the non-timely introduction of food and a range of maternal social demographic and health behaviour factors including age, education level, ethnicity and smoking habits.

The research team hope that the findings will helpinform policies which provide appropriate and targeted support to mothers, whanau/families.

The team plan to continue to use data from the Growing Up in New Zealand study to look at the impact of non-timely food introduction on child and youth health and wellbeing outcomes.

This research was led by Sara Ferreira, a master’s student from the University of Sao Paulo (USP), Brazil. Sara was supervised by Prof Dirce Marchioni (USP) and Senior Research Fellow Teresa Gontijo de Castro (University of Auckland).

You can read the Prevalence and maternal determinants of early and late introduction of complementary foods study on Cambridge University Press website.

About Growing Up in New Zealand

• Growing Up in New Zealand is a University of Auckland study, managed by UniServices Limited.
• The study is funded by the New Zealand Government. 
• It is the country’s largest contemporary longitudinal study of child development.
• It follows more than 6,000 children whose mothers resided in the Auckland, Counties Manukau and Waikato District Health Board areas during pregnancy. 
• The study has followed these children from before birth and intends to continue following them until the children are at least 21-years-old. 
• The study has been specifically designed to reflect the diverse lives of children growing up in the complex world of 21st century New Zealand.
• It is especially focused on what works to optimise child development and wellbeing.
• The information collected by Growing Up in New Zealand aims to help to shape government policies to better meet the needs of children and families in New Zealand.
• Growing Up in New Zealand has conducted more than 100,000 interviews and collected more than 60 million pieces of data in the past ten years. 
• Children and families generously give their time to the study for free, with face-to-face data collection waves taking place every two to three years.
• Find out more about Growing Up in New Zealand’s research at www.growingup.co.nz