THURSDAY, Aug. 29, 2024 (HealthDay News) -- Breastfeeding helps women shed those extra pounds of "pregnancy weight," a new study finds, and the effect is even more pronounced for moms who were overweight before their pregnancy.

Among women who exclusively breastfed their baby during its first year, women who were normal weight prior to pregnancy lost weight, but still retained about three extra pounds of their pregnancy weight, reported a team of researchers in Singapore.

However, breastfeeding new moms who were already obese or overweight before their pregnancy lost all their added pregnancy weight, plus an average of another half-pound on top of that, the same team found.

Women who chose not to breastfeed or had a mix of formula plus breastfeeding retained much more pregnancy weight, with average weight gains at 12 months post-delivery of about 6 and 8 pounds, respectively.

"In this year-long study, we made an interesting discovery -- an additional benefit [of breastfeeding] for women with high BMI," said study lead author Dr. Loy See Ling, of the department of reproductive medicine at KK Women’s and Children’s Hospital in Singapore.

"Due to hormonal factors, there is a re-distribution and management of their body fat to the extent that there is an opportunity for them to lose more than the postnatal weight gain," Ling explained in a hospital news release.

Her team published its findings recently in the journal Nutrients.

The new study tracked the weight of 379 first-time mothers for 12 months after childbirth, noting their baby-feeding practices -- exclusive breastfeeding, a mix of breastfeeding and formula feeding or exclusively formula feeding. 

The finding that breastfeeding helps women shed excess pounds was expected, but the differences in the benefit linked to pre-pregnancy weight was not.

Starting out life with a breastfeeding mom who's already on the path to better health could have long-term benefits, Ling said.

"Encouraging exclusive breastfeeding alongside targeted lifestyle changes may serve as an effective intervention for enhancing the metabolic health of young mothers and their families after childbirth, especially if they have high BMI," she noted.

Breastfeeding could lower "the likelihood of mother and child developing obesity, diabetes and cardiovascular diseases in the later years," she explained.

All of this is especially true for women who have multiple children, she added.

"In women with multiple pregnancies, each instance of retained weight can accumulate, resulting in a significant long-term weight increase that can impact pregnancy outcomes and long-term health, thereby increasing the risk of obesity, diabetes and heart diseases for both mother and child," Ling explained.

More information

Find out more reasons why breastfeeding is good for mom and baby at the March of Dimes.

SOURCE: KK Women’s and Children’s Hospital, news release, Aug. 26, 2024