Childhood obesity: Breast is not necessarily best

Long-term research into obesity suggests that being breastfed as a child does not help prevent obesity later in life, a finding that contradicts guidelines in the United States and elsewhere.

Investigators in the United States looked at the health of 35,000 nurses working in the US between 1989 and 2001.

They asked the nurses' mothers to report on their breastfeeding habits when their child was a newborn, while the nurses themselves were asked to report their height, their current weight and their weight at 18.
The nurses were also asked to recall their body shape at ages five and 10 using a nine-level figure drawing.

Duration of breastfeeding did not affect the body mass index (BMI) -- a key indicator of fat -- in adulthood, according to their paper, which appears in the International Journal of Obesity.

Women who had been breastfed for more than nine months had a risk of becoming overweight or obese that was similar to that of women who had been breastfed for less than a week or exclusively bottle-fed.

"Breastfeeding, as good as it is, is not a solution to the obesity epidemic," Karin Michels, associate professor at Harvard Medical School and lead author of the study, told AFP.

"It's important to realize that there are much more important causes and reasons for the obesity epidemic."

The researchers found that women who had been breastfed for several months were indeed slightly slimmer in early childhood compared with those who had been bottle-fed.

But this difference is of "borderline statistical significance," according to Michels.

The mooted reason: breast-fed infants start off skinnier, but this is probably due to the natural limitations of available food in their first year of life -- and the difference does not extend to later years.

Breastfeeding does provide plenty of other benefits to mother and child, Michels pointed out.

Its vital nutrients help the child to build up its immune system and, as has been recently discovered, lessens a mother's risk for diabetes and heart disease, Michels said.

The paper contradicts the recommendations of the US Centers for Disease Control (
CDC) and the European Union's Childhood Obesity Programme, which promote breastfeeding as a method for controlling childhood obesity, with the eventual aim of curbing adolescent and adult obesity.

In another study released on Tuesday, the British journal Archives of Disease in Childhood concluded that primary schoolchildren should not be routinely screened for obesity and weight problems if there are no means to treat them.

The British government has introduced population weight monitoring in primary schools.

But the authors, led by Marie Westwood of the University of York, northern England, found no evidence to say the screening strategy worked and suggested it may even be potentially harmful if counselling and other help were not available.

Obesity is gaining pandemic proportions in many developed countries but also in emerging economies. Experts point the finger at sedentary lifestyle, persistent snacking and food that is rich in calories. Genetic factors, too, may be significant.