Children from the poorest families in Ireland are 230% more likely to be obese by the age of three than their peers from higher-income families, new research has found.

According to the Economic and Social Research Institute (ESRI), the environment that a child grows up in has life-long effects on both their physical and psychological wellbeing.

It carried out research based on two ongoing studies - Growing Up in Ireland (GUI) and the National Longitudinal Study of Ageing (TILDA) - and found that childhood represents a ‘critical period'. After this, remedial treatment is often less effective and very expensive.

"Equality of opportunity for children is permanently undermined if they begin their lives at a disadvantage in terms of physical, psychological, emotional and social wellbeing," the ESRI commented.

The research found that the lower the income of a family, the lower the birth weight of a baby. Yet once the child is born, the risk of obesity jumps. By the age of three, the risk is 75% higher for children who are in the bottom 50% of the income distribution. Children in the bottom 20% are 230% more likely to be obese by three years of age.

The psychological wellbeing of children from poorer families is also lower. By the age of nine, those in the bottom 50% of the income distribution are twice as likely to suffer from serious behavioural and emotional problems.

Meanwhile, the research also found that a child's environment contributes to their risk of developing chronic illnesses later in life. For example, those who grow up in poorer households have an increased risk of developing heart disease, depression and anxiety later on.

"This research adds to a growing international evidence base that shows how children's early life environments determine not only their physical health and risk of disease, but may also contribute to childhood and adult criminality, educational failure, family breakdown and mental health," the ESRI said.

It emphasised that ‘upstream' interventions - those that focus on the causes of health and social problems - ‘will be more effective and cheaper than ‘downstream' services to deal with the consequences'.

The research also noted that Ireland's child poverty rate is high compared to some other European countries, yet cash benefits to families with children are higher here than in most other countries in Europe.

"This paradox results from high levels of worklessness in households with children in Ireland. Measures which facilitate employment may be more effective at reducing child poverty than increases in cash benefits. Maintaining financial support for families with children is important, but improved provision of family services may be more effective at increasing child welfare," the ESRI said.

It noted that one way of improving the health and welfare of children and adults in the community is via well-resourced community health services, especially public health nurses.

It also emphasised the importance of good pre-school education, which it said, improves the health, social skills and educational success of children from poorer families.

"With a tight national budget we need to think carefully about investing for the future. Ireland's future prosperity depends on having an educated, creative and competitive workforce. By investing in early childhood we will be developing healthier, happier and more productive adults for all our tomorrows and saving money in the process," commented Prof Richard Layte of the ESRI.