Infant Health

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Breastfeeding has been found to generally reduce a child’s current and future risk of overweight and obesity. Some of the latest studies are below. Find out about the impact of breastfeeding on maternal overweight and obesity in our maternal health research section.

One in five UK infants are obese at age 14 – but children who were breastfed are less likely to be obese

A new study from the Centre for Longitudinal Studies (CLS) at the UCL Institute of Education has found that one in five young people born in the UK at the turn of the century was obese by the age of 14, and a further 15 per cent were found to be overweight. Researchers analysed information on more than 10,000 teenagers who are taking part in the Millennium Cohort Study. Rates of excess weight varied by country, with almost 40 per cent of young people in Northern Ireland overweight or obese, compared to 38 per cent in Wales, and 35 per cent in both Scotland and England. As well as mother’s education and parents’ home ownership being factors impacting the likelihood of children becoming obese, researchers found that children who were breastfed as infants had lower odds of being overweight and obese at age 14.

Fitzsimons, E, & Pongiglione, B, Prevalence and trends in overweight and obesity in childhood and adolescence: Findings from the Millennium Cohort Study, with a focus on age 14. Centre for Longitudinal Studies Working paper 2017/16.

Relationship between breastfeeding and early childhood obesity

This Swedish Prospective Longitudinal study of 30,508 infants explored the potential link between breastfeeding in infancy and obesity at age four. It found that any breastfeeding up to 9 months was linked to a reduced risk of childhood obesity at four years. Other factors influencing child obesity were child sex, maternal education, maternal body mass index, and maternal smoking.

Wallby, T, et al (2017), Relationship Between Breastfeeding and Early Childhood Obesity: Results of a Prospective Longitudinal Study from Birth to 4 Years. Breastfeeding Medicine, Vol. 12, No. 1: 48-53, doi/full/10.1089/bfm.2016.0124

The effects of breastfeeding on childhood BMI: a propensity score matching approach

A study of the impact of breastfeeding on childhood BMI found that breastfeeding had a particularly strong effect on BMI in older children, when breastfeeding was prolonged and exclusive. At 7 years, children who were exclusively breastfed for 16 weeks had a BMI 0.28 kg/m2 lower than those who were never breastfed, a 2% reduction from the mean BMI of 16.6 kg/m2. The authors suggested that breastfeeding should be encouraged as part of a wider lifestyle intervention to reduce childhood BMI.

Gibson, L, et al (2016) The effects of breastfeeding on childhood BMI: a propensity score matching approach. Journal of Public Health, doi: 10.1093/pubmed/fdw093

Effect of Exclusive Breastfeeding Among Overweight and Obese Mothers on Infant Weight-for-Length Percentile at 1 Year

This study found that exclusive breastfeeding for 4 months among overweight and obese mothers resulted in less increase in W/L percentiles in the first year. Authors noted the need for concerted efforts to support breastfeeding among obese and overweight mothers, who often have difficulties initiating and maintaining breastfeeding.

Hui, Y, et al (2016) Effect of Exclusive Breastfeeding Among Overweight and Obese Mothers on Infant Weight-for-Length Percentile at 1 Year. Breastfeeding Medicine, Volume: 12 Issue 1, doi:10.1089/bfm.2016.0071

Systematic review of interventions to reduce early overweight and obesity

This review identified interventions designed to reduce the risk of overweight/obesity that were delivered before birth or during the first two years of life, with outcomes reported from birth to seven years of age. It was found that nutritional and/or responsive feeding interventions targeted at parents improved feeding practices and had some impact on child weight, while breastfeeding promotion and lactation support for mothers had a positive effect on breastfeeding but not child weight. Interventions that aim to improve diet and parental responsiveness to infant cues showed most promise in terms of self-reported behavioural change.

Redsell, S, et al (2015). Systematic review of randomised controlled trials of interventions that aim to reduce the risk, either directly or indirectly, of overweight and obesity in infancy and early childhood. Maternal & Child Nutrition, DOI: 10.1111/mcn.12184

Breastfeeding and obesity

This study examined the relationship between >4 months of full breastfeeding and overweight/obesity in children living in Germany. The authors conclude that breastfeeding does have a beneficial effect on childhood overweight and obesity, with the effect strongest in children of primary school age.

Grube, MM et al (2015) Does Breastfeeding Help to Reduce the Risk of Childhood Overweight and Obesity? A Propensity Score Analysis of Data from the KiGGS Study. Plos One, DOI: 10.1371/journal.pone.0122534

The association between breastfeeding and childhood obesity

The authors systematically searched PubMed, EMBASE and CINAHL Plus with Full Text databases. Twenty-five studies with a total of 226,508 participants were included in this meta-analysis. Results showed that breastfeeding was associated with a significantly reduced risk of obesity in children. Categorical analysis of 17 studies revealed a dose-response effect between breastfeeding duration and reduced risk of childhood obesity.

Yan et al (2014). The association between breastfeeding and childhood obesity: a meta-analysis. BMC Public Health, 14.  doi:10.1186/1471-2458-14-1267

Breastfeeding duration and weight gain trajectory in infancy

This prospective, observational study tested the hypothesis that infants at higher risk for obesity were more likely to be members of a rising weight-for-length (WFL) z score trajectory if breastfed for shorter durations. The authors found that infants at the highest risk for rising weight patterns appeared to benefit the most from longer breastfeeding duration. They suggest that targeting mothers of high-risk infants for breastfeeding promotion and support may be protective against overweight and obesity during a critical window of development.

Carling et al (2014). Breastfeeding duration and weight gain trajectory in infancy. Pediatrics, doi: 10.1542/peds.2014-1392

Timing of solid food introduction and the risk of obesity

This study examined the association between timing of introduction of solid foods during infancy and obesity at 3 years of age. This research studied 847 children in Project Viva, a prospective pre-birth cohort study. Among formula-fed infants or infants weaned from breastmilk before the age of 4 months, introduction of solid foods before the age of 4 months was associated with increased odds of obesity at age 3 years.

Susanna Y. Huh, Sheryl L. Rifas-Shiman, Elsie M. Taveras, MD, Emily Oken, Matthew W. Gillman, (2011) Timing of Solid Food Introduction and the Risk of Obesity in Preschool-Aged Children, Pediatrics, Feb 2011, DOI:10.1542/peds.2010-0740

Early bottle-feeding impacts on ability to self-regulate

A study was carried out to investigate whether infants’ self-regulation of milk intake is affected by feeding mode (bottle versus breast) and the type of milk in the bottle (formula versus expressed breast milk). Participants in a large study received monthly questionnaires during their infant’s first year, and complete data were available for 1,250 infants. The authors concluded that infants who are bottle-fed in early infancy are more likely to empty the bottle or cup in late infancy than those who are fed directly at the breast. Bottle-feeding, regardless of the type of milk, is distinct from feeding at the breast in its effect on infants’ self-regulation of milk intake.

Li R, Fein SB, and Grummer-Strawn LM (2010) Do Infants Fed From Bottles Lack Self-regulation of Milk Intake Compared With Directly Breastfed Infants? Pediatrics 10 May 2010.


Three good and moderate meta-analyses of methodological quality which infer that the risk of obesity is reduced in later life by breastfeeding have been published. Harder (2005) reviewed 17 studies including over 120,000 babies. They concluded that every month of breastfeeding was found to be associated with a 4% decrease in risk. Arenz (2004) reviewed 9 studies, 69,000 babies and concluded that breastfeeding appears to have a small (odds ratio 0.78, 95% CI (0.71, 0.85) but consistent protective effective against obesity. Owen (2005) reviewed 61 studies, 29,800 babies again found a reduced risk of obesity in later life even when confounding variables such as parental obesity, maternal smoking and social class were taken into account.

Harder T, Bergman R, Kallischnigg G et al (2005) Duration of breastfeeding and risk of overweight: a meta-analysis. American Journal of Epidemiology; 162:397-403

Arenz S, Ruckeri R, Koletzko B et al (2004) Breastfeeding and Childhood obesity: a systematic review. International Journal of Obesity related metabolic Disorders: 28: 1247-1256

Owen C, Martin R, Whincup P et al (2005) The effect of breastfeeding on mean body mass index throughout life: a quantitative review of published and unpublished observational evidence. Am. J. Clin. Nutr; 82: 1298-1307

Breastfeeding and lower BMI

This study of 2,347 Dutch children found that children who were breastfed for more than 16 weeks had a lower BMI at one year compared with children who hadn’t breastfed. A high BMI at one year of age was strongly associated with a high BMI from age one to seven.

Salome Scholtens, Ulrike Gehring, Bert Brunekreef, et al. Breastfeeding, weight gain in infancy, and overweight at seven years of age. American Journal of Epidemiology 2007; doi:10.1093/aje/kwk083