Breastfeeding Linked To Thinness, Even Decades Later

Breastfeeding is best for babies, offering nutritional and immunological benefits unmatched by formula. Breastfeeding is also beneficial to women, protecting a mother against breast cancer as well as helping her lose her pregnancy weight faster. A new study published in the International Journal of Obesity also indicates that women who breastfed continue to keep the weight off better even decades later.

In the study conducted by researchers in England, the researchers looked at data from nearly 750,000 participants in the Million Women Study, which is a broad ongoing national study of women’s health involving mostly women aged 50 to 64 in the United Kingdom. The researchers discovered that women with children tended to have higher body mass indexes (BMI) later in life than women without children. Calculated from weight and height, BMI is one screening tool for overweight and obesity.

Although women who had children were heavier in general, women who had breastfed their babies tended to have lower BMI than non-breastfeeding women. In other words, breastfeeding continues to offer benefits in terms of weight long after the breastfeeding has ceased.

For every six months of breastfeeding, BMI decreased by about 1 percent on average.

As The Huffington Post reports, Dr. Kirsty Bobrow, a researcher at the University of Oxford and one of the authors of the study, comments:

“These are long-term effects. For women in this study, childbearing and breastfeeding occurred on average 30 years before women’s weights and heights were recorded.”

As Dr. Bobrow further explains on MSNBC:

“We already know breastfeeding is best for babies, and this study adds to a growing body of evidence that the benefits extend to the mother as well, even 30 years after she’s given birth.”

Even the modest 1 percent decrease in BMI associated with breastfeeding is significant because overweight and obesity are linked to myriad health problems including diabetes and cardiovascular disease. Encouraging women to breastfeed could be a way to fight obesity in the long term.

Breastfeeding burns about 500 calories a day. One explanation for the long-term weight reduction associated with breastfeeding is the “reset hypothesis.” During pregnancy, certain fats accumulate, and insulin resistance as well as lipid and triglyceride levels increase. Breastfeeding may play a key role in reversing the changes by “resetting” maternal metabolism.

However, further research needs to be conducted to establish the mechanisms behind breastfeeding and lower BMI later in life.

The researchers also caution that the relationship between breastfeeding and thinness has not yet been determined to be causal. Women who breastfed their babies just tend to have lower body mass indexes decades after breastfeeding stops. The message, however, seems to be clear: Breastfeeding is beneficial to mothers in the short term and the long term.

Did you breastfeed your children?