TOPLINE:

Vegan and vegetarian diets were associated with increased odds of being underweight in early infancy, the first 60 days of life, compared with an omnivore diet, with these differences less pronounced by 24 months.

METHODOLOGY:

• Researchers conducted a retrospective cohort study using data from approximately 1.2 million children born in Israel between 2014 and 2023, sourced from a national research platform.
• They analyzed the growth patterns and weight status of infants from households that followed vegan (0.3%), vegetarian (1.2%), or omnivorous (98.5%) dietary patterns, as reported by caregivers.
• The primary outcome was infant length, measured in centimeters and as World Health Organization length-for-age z scores.
• The secondary outcomes were weight, head circumference, and birth weight (birth weight-for-gestational age centiles were derived from sex-specific standards).
• Data on anthropometric measurements and breastfeeding status were extracted from the Family Child Center database.

TAKEAWAY:

• Infants in vegan households had the lowest mean birth weight-for-gestational age centiles, followed by those in the vegetarian and omnivorous groups (P < .001 for all). Mothers in the vegan group had longer durations of both full and partial nursing than those in the vegetarian and omnivorous groups.
• Infants from vegan households had a higher likelihood of being underweight in early infancy than those from omnivorous households (adjusted odds ratio [aOR], 1.37; P = .001). Infants from vegetarian households also had increased odds of being underweight compared with those from omnivorous households (aOR, 1.21; P < .001).
• By 24 months, the prevalence of stunting, underweight, and overweight was low, with no significant differences between the dietary groups.
• Children in the vegan group had lower length, weight, and head circumference metrics than those in the omnivorous group in minimally adjusted models, but these differences were attenuated after adjusting for birth weight.

IN PRACTICE:

“These findings suggest that a vegan family dietary pattern may support healthy growth in infancy when appropriately planned. Nutritional counseling during pregnancy and early infancy, combined with regular growth monitoring, may help ensure optimal infant development,” the authors wrote.

SOURCE:

The study was led by Kerem Avital, MPH, of the Department of Epidemiology, Biostatistics, and Community Health Sciences at the Ben-Gurion University of the Negev in Be’er Sheva, Israel. It was published online on February 5, 2026, in JAMA Network Open.

LIMITATIONS:

Most data were collected in the first year, with nearly 40% of children lacking measurements at 24 months or older. Dietary patterns were reported by the caregivers, and detailed information about the diets of mothers and infants was lacking. The study did not standardize definitions for vegetarian and vegan diets.

DISCLOSURES:

The study did not receive any specific funding. One author disclosed volunteering at the Physicians Association for Nutrition Israel.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.