Breastfeeding does not appear to lower a child’s risk of being overweight or obese.

The finding came from a new study led by researchers at the University of Bristol, England, and was published in JAMA.

Even though no benefits regarding bodyweight were found, the authors emphasized that the breastfed children in their study had fewer episodes of gastrointestinal infection and atopic eczema during infancy, and better cognitive development by the age of 6.5 years.

The scientists examined the outcomes of an intervention that successfully improved the duration and exclusivity of breastfeeding during infancy.

Almost 14,000 healthy children from Belarus, Eastern Europe, were involved in the study, which indicated that the duration and exclusivity of breastfeeding did not lower the risk of being overweight or obese among the kids at age 11.5 years.

Past research has suggested that greater duration and exclusivity of having been breastfed makes a child less likely to become obese.

A previous study said that breastfeeding for more than three months helps prevent obesity in children.

“However, breastfeeding and growth are socially patterned in many settings,” and observed links between these variables are explained to a certain extent by confounding factors, the authors said.

The team of investigators, led by Richard Martin, Professor of Clinical Epidemiology at the University of Bristol, observed the effects of an intervention to encourage greater duration and exclusivity of breastfeeding on child adiposity (body fat) and circulating insulin-like growth factor (IGF)-I, which regulates growth.

The randomized controlled trial took place in 31 Belarusian maternity hospitals and their associated clinics.

The volunteers were randomly divided into two groups:

  • The breastfeeding promotion intervention group
  • The usual practices group

Participants were 17,046 breastfeeding mother-infant pairs who registered for the study in 1996 and 1997. Of those subjects, 13,879 (81.4%) were followed up between January 2008 and December 2010 at a median age of 11.5 years.

The WHO/UNICEF Baby-Friendly Hospital Initiative (World Health Organization/United Nations Children’s Fund) was used as the model for the breastfeeding promotion intervention.

The key outcome measures included:

  • body mass index (BMI)
  • percent body fat
  • waist circumference
  • fat and fat-free mass indices (FMI and FFMI)
  • triceps and subscapular skinfold thicknesses
  • whole-blood IGF-I
  • overweight and obesity

Results showed that the children in the intervention group had considerably increased breastfeeding duration and exclusivity compared to the control group – at three months, exclusively (43.3% vs. 6.4%) and predominantly (51.9 vs. 28.3%) breastfed; at 6 months, exclusive (7.9% compared to 0.6%) and predominant breastfeeding (10.6% compared to 1.6) were both reduced, but more common in the intervention group; and at 1 year, 19.7% (intervention) vs. 11.4% (control), were still breastfeeding to some degree.

When the children were a median 11.5 years old at follow-up, the scientists found no notable differences between those in the experimental group and control group for the main outcomes.

The experts concluded:

“Among healthy term infants in Belarus, an intervention to improve the duration and exclusivity of infant breastfeeding did not prevent overweight or obesity, nor did it affect IGF-I levels among these children when they were aged 11.5 years.

Nevertheless, breastfeeding has many health advantages for the offspring, including beneficial effects demonstrated by our PROBIT trial on gastrointestinal infections and atopic eczema in infancy and improved cognitive development at age 6.5 years.”

Written by Sarah Glynn