A new observational study suggests that pregnant women who more closely follow the Planetary Health Diet tend to consume higher amounts of several important nutrients, including folate, iron, calcium and fiber. The findings offer early evidence that a more plant-forward eating pattern can align with many nutritional goals during pregnancy.
That does not mean the diet fully meets pregnancy needs or improves health outcomes. The study measured nutrient intake in early pregnancy, not birth outcomes or long-term health, and researchers note that supplementation remains necessary for certain nutrients.
The study, published in the British Journal of Nutrition, analyzed dietary data from 678 pregnant women in Ireland. Participants completed food frequency questionnaires during the first trimester, and researchers used those responses to calculate how closely each participant’s diet aligned with the Planetary Health Diet, a dietary pattern that emphasizes plant-based foods while limiting red and processed meat.
Women with higher adherence scores had higher reported intakes of several nutrients that are important during pregnancy, including folate, iron, calcium and fiber. However, the diet did not fully meet all recommended nutrient levels. As in standard prenatal guidance, supplementation for nutrients such as folate, vitamin D and iodine was still advised.
“The findings showed that adhering to a planetary health diet in pregnancy results in better intakes of many important nutrients in pregnancy and, at the same time, supports environmental sustainability,” said Prof Fionnuala McAuliffe, senior author of the study.
For U.S. readers, the Planetary Health Diet may be best understood as a flexible, plant-forward approach rather than a strict vegetarian or vegan diet. It prioritizes fruits, vegetables, whole grains, legumes and nuts, while allowing smaller amounts of animal-based foods. The goal is to balance human health with environmental considerations, though this study focused only on nutrient intake.
The results reflect associations, not cause and effect. Because the study was observational and based on self-reported dietary data, it cannot determine whether following this pattern leads to better pregnancy outcomes or improved health for mothers and babies. It is also based on a specific population in Ireland, which may differ from U.S. dietary patterns and food availability.
Still, the findings suggest that diets with more plant-based foods can be compatible with many nutritional targets during pregnancy, as long as known gaps are addressed. Rather than replacing standard prenatal guidance, the study supports the idea that dietary pattern and nutrient adequacy can be considered together.
This research was supported by the Health Research Board Ireland, the Health Research Centre for Health and Diet Research, The National Maternity Hospital Medical Fund, the European Union’s Seventh Framework Programme and Science Foundation Ireland, which included a research grant from PrecisionBiotics Group Ltd.