The research was carried out by three scientists with the Laboratory for Anthropogenetics at the VUB and the Centre for Youth Health Care at the Catholic University of Leuven and will be published in the February issue of Annals of Human Biology.

The team’s research concerns the parameters for determining normal growth patterns in children as a whole, which are based on World Health Organisation growth curves from data on children aged 0 to five years from a variety of countries.

However, children in the developed world are generally larger and heavier than in other parts of the world, which leads to them being considered overweight in comparison to WHO curves. According to the team, it would be more accurate to measure Flemish babies against growth curves determined by Flemish data – and they have provided the necessary measures.

Those reveal that children are getting taller and heavier across the board: the average 18-year-old male is now 1.2 centimetres taller than his counterpart 10 years ago; for girls the difference is 0.9cm. At the same time, 18-year-olds are one kilogram heavier on average than a decade ago.

The scientists stress that the slower growth of breastfed babies is normal and that parents should not consider it a disadvantage. The study looked at a representative sample of 3,287 Flemish children under the age of three and measured their length or height, weight, Body Mass Index and head circumference.

In Flanders, 68% of babies are breast fed at birth, but the proportion drops off suddenly: at six months, the figure is 25%. A large number of mothers return to work after the end of the 16-week statutory maternity leave period, which makes continued breast feedings difficult or impossible. Babies in poor families where the mother has a low educational level are less likely to breast feed, though this is not true for families of immigrant origin of a similar social level.

The figures show that while weight, BMI and head circumference in breast-fed babies all conform to Flemish growth curves – and all are ahead of WHO curves – that is not the case for length. “In the first year of life, the growth of children who are breast fed is slowed slightly,” says researcher Mathieu Roelants. “But a short while later, those children make up their delay. In any case, breast feeding remains the best way to feed young children.”