The amount of weight a new-born baby gains in its first month is directly linked to its IQ later in life, according to a new study.
Growth in head circumference is also important, say researchers who studied data from more than 13,800 Australian children who were born full-term.
There are a lot of possible reasons for delayed growth and feeding problems, says lead author Dr Lisa Smithers. Parents should seek help as early as possible if they are worried.
‘‘Babies should be fed on demand and should never be forced to eat,’’ she says.
Babies who increase their birth weight by 40 per cent in the first four weeks have 1.5-point IQ advantage over children who gain 15 per cent, according to the research report published in the journal Pediatrics.
‘‘Head circumference is an indicator of brain volume, so a greater increase suggests more rapid brain growth,’’says Smithers from the University of Adelaide’s School of Population Health.
Overall, newborn children who grow faster in the first four weeks have higher IQ scores later in life, she says.
Those children who gain most weight score especially high on verbal IQ at age six.
Previous studies have shown the association between early postnatal diet and IQ, but this is the first study of its kind to focus on the IQ benefits of rapid weight gain in the first month of life for healthy newborn babies, she says.
One or two IQ points are significant but it is not the end of the world if a child misses out on them,’’ says Swinburne University’s Professor Con Stough, an internationally recognised authority on human intelligence.
‘‘You have to say 1.5 IQ points at age six is not massive, but I would rather have them than not have them.
‘‘The research shows this type of nutritional need is very important. Nutrition at all ages is important.’’