Human milk composition tied to maternal overweight/obesity, low supply
14 Jan 2026
Maternal overweight/obesity (OW) can alter the composition of human milk (HM) and affect infant milk intake, suggests a study.
Using the test-weigh method, the investigators measured 24-h milk production at 1‒5 months postpartum. They obtained HM samples, demographic, obstetric, and infant data from 225 participants, then analysed macronutrients (fat, protein, lactose, and glucose) and hormones (estrone, estradiol, progesterone, leptin, adiponectin, and insulin).
Maternal OW correlated with higher concentrations of HM fat (β, 5.2, 95 percent confidence interval [CI], 6.5 x 10-3 to 10.4), leptin (β, 197.4, 95 percent CI, 125.8‒269.1), insulin (β, 5.9, 95 percent CI, 2.5‒9.2), and higher infant intake of leptin (β, 135.9, 95 percent CI, 86.3‒185.4) and insulin (β, 3.2, 95 percent CI, 1.3‒5.0).
In participants with low milk supply (LMS), infant total intakes of fat (β, −9.5, 95 percent CI −1.4 to −5.4), carbohydrates (β, −6.0, 95 percent CI, −10.2 to −1.8), estrone (β, −9.9, 95 percent CI, −14.5 to −5.4), estradiol (β, −3.5, 95 percent CI, −5.1 to −1.9), leptin (β, −55.9, 95 percent CI, −109.0 to −2.7), and adiponectin (β, −3.9, 95 percent CI, −6.0 to −1.7) were lower despite having increased concentrations of HM protein, lactose, insulin, estrone, and progesterone.
Furthermore, infant carbohydrates (β, 11.5 × 10−3, 95 percent CI, 4.6 × 10−3 to 18.4 × 10−3), energy (β, 1.0 × 10−3, 95 percent CI, 0.3 × 10−3 to 1.6 × 10−3), and 24-h total intakes (β, 1.7 × 10−3, 95 percent CI, 1.1 × 10−3 to 2.4 × 10−3) positively correlated with infant weight-for-age z-score.
“LMS impacts infant weight gain by limiting milk volume, underscoring the importance of timely LMS detection to ensure adequate infant nutrition,” the investigators said.