A daily 400-calorie nutrition sachet in pregnancy, then while breastfeeding: 1,568 babies in Nepal had no growth advantage at six months

In places where many women begin pregnancy short of food, energy and micronutrients, a daily ready-to-eat supplement can sound like an obvious way to help a baby grow. The World Health Organization recommends balanced energy-protein supplements for undernourished populations during pregnancy. What happens if that help continues through breastfeeding, when a baby's growth can falter quickly, has been much less clear.

The Maternal Infant Nutrition Trial, or MINT, tested that question in Sarlahi, rural southern Nepal. It used a 2 by 2 design: households were allocated to receive a fortified balanced energy-protein food during pregnancy or not, then allocated again after a live birth to receive it through the first six months of lactation or not. The daily portion was a 72-gram peanut-based paste designed to provide about 400 calories, 14 grams of protein and multiple micronutrients. Both groups also received the same nutrition, hygiene, breastfeeding and infant-care counselling, so the study was testing the added food rather than advice alone.

The new report followed 1,554 mothers and 1,568 infants who were randomised after delivery. At six months, there was no sign that either pregnancy supplements or lactation supplements changed average length for age, the main outcome. The estimated difference in length-for-age score was 0.01 for pregnancy supplementation (95% confidence interval -0.10 to 0.12) and -0.02 for lactation supplementation (-0.13 to 0.09). Those ranges include a small benefit, no difference and a small disadvantage. Weight for length, weight for age, head circumference, arm circumference and the proportions of babies who were stunted, wasted or underweight also showed no statistically clear difference. The subset measured again at 12 months did not change the picture.

This is not a result against good food in pregnancy or breastfeeding. The study tested one particular product, timing and setting, and it did not measure every possible benefit. It was unblinded, as food-versus-no-food trials usually have to be, and the paper's primary infant-growth analysis began after delivery, so it cannot settle every question about birth outcomes. But it was much larger than the small supplement trials that often shape expectations, and it deliberately separated pregnancy from lactation. Its plain finding is valuable: adding this fortified food did not, by itself, prevent early growth faltering. The authors say other strategies are needed alongside efforts to improve mothers' diets and food security.