Infants residing in households observing a vegan diet may exhibit growth trajectories similar to those in households following an omnivorous diet, with modest early differences in underweight prevalence narrowing by age 24 months, according to a nationwide retrospective cohort study.
In the study, investigators led by Kerem Avital, MPH, of the Ben-Gurion University of the Negev, analyzed data from 1.2 million singleton infants born between January 2014 and December 2023. Among them, 99% were from omnivorous households, 1% were from vegetarian households, and less than 1% were from vegan households. Family dietary pattern was recorded as a caregiver-reported household-level item at or following the introduction of complementary foods, typically at age 6 months or older.
Mean Growth Differences Minor
Mean differences in length and weight between the dietary groups were clinically minor throughout the first 24 months of life, with World Health Organization z score differences consistently 0.2 or less. On average, infants from vegan households were less than 0.5 cm shorter and approximately 100 g lighter at birth compared with infants from omnivorous households. These modest gaps largely disappeared following adjustment for birth weight.
Stunting prevalence, defined as length-for-age z scores of less than –2, was similar across groups in early infancy at approximately 7%. By age 24 months, stunting prevalence declined to 3% among infants from omnivorous households, 3% among those from vegetarian households, and 4% among those from vegan households, with no statistically significant differences following adjustment.
Early Underweight More Common in Vegan Group
The primary divergence emerged in early infancy underweight risk, defined as weight-for-length z score less than –2. Infants from vegan households had 1.37 times the risk of being underweight compared with those from omnivorous households in adjusted models. Infants from vegetarian households had 1.21 times the risk.
Despite these relative differences, underweight was uncommon. During early infancy, underweight prevalence was 7% among infants from vegan households, 6% among those from vegetarian households, and 5% among those from omnivorous households.
By age 24 months, underweight prevalence fell below 1% across all dietary groups, with no statistically significant differences. Overweight prevalence remained low and similar across the groups at both time points.
Methodology and Longitudinal Analysis
The investigators used data from TIMNA, the Israeli Ministry of Health’s national research platform, which compiles records from Family Child Centers providing free universal preventive care. The data set included more than 8.8 million length measurements, 11.3 million weight measurements, and 9.3 million head circumference measurements.
The investigators also used linear mixed-effects models with restricted cubic splines assessed associations between family dietary patterns and repeated anthropometric measurements. Sequential models adjusted for age and sex, followed by perinatal factors, maternal characteristics, area-level sociodemographic variables, and birth weight. Generalized additive mixed models estimated age-specific probabilities of stunting, underweight, and overweight over time.
In minimally adjusted models, infants from vegan households had lower length-for-age, weight-for-age, head circumference, and weight-for-length z scores compared with infants from omnivorous households. These differences were attenuated following additional adjustment for birth weight, with length-for-age z score differences crossing zero.
Birth Weight and Breastfeeding Patterns
Birth weight appeared to partially explain the observed growth differences. Mean birth weight was lower among infants from vegan households compared with omnivorous households (3.2 vs 3.3 kg). Low birth weight, which the investigators defined as less than 2.5 kg, occurred in 6% of infants from vegan households compared with 5% of infants from vegetarian households and 5% of those from omnivorous households. The prevalence of small for gestational age followed a similar pattern (11% vs 7% and 7%, respectively).
Breastfeeding duration was longer among mothers from vegan households. Full nursing for 1 to 6 months was reported by 65% of vegan households compared with 57% of vegetarian households and 50% of omnivorous households. In addition, partial nursing for 12 months or longer was reported by 47% of vegan households compared with 37% and 27%, respectively.
Maternal Characteristics
Mothers from vegan households were older at delivery compared with those from vegetarian and omnivorous households (mean age 33 vs 32 and 30 years, respectively), had higher area-level income indices, more commonly resided in predominantly Jewish localities (82% vs 73% and 62%), and had lower parity.
Limitations
The study had several limitations. Data were limited to Ministry of Health– and municipality-operated Family Child Centers, representing approximately 70% of infants, with health maintenance organization–operated centers excluded. Most visits occurred during the first year of life, and 37% of infants lacked measurements at age 24 months or older.
Family dietary pattern was assessed once, wasn't updated longitudinally, and didn't capture individual maternal or infant intake. Definitions of vegetarian and vegan weren't standardized, and dietary subtypes weren't distinguished. Data on complementary feeding, maternal diet and supplement use, prepregnancy body mass index, and maternal smoking were unavailable. Finally, the follow-up period extended only to age 30 months.
Clinical Implications
The investigators noted that well-planned vegan diets may meet children’s nutritional needs with appropriate supplementation and monitoring. They emphasized the importance of nutritional counseling and pediatric follow-up among infants and children from vegan households as well as for pregnant and breastfeeding mothers.
“In developed countries, the growth trajectories observed in children from vegan households seem broadly reassuring,” the study authors wrote. “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,” they concluded.
Disclosures: No external funding was reported. Mr. Avital reported volunteering at the Physicians Association for Nutrition Israel, a nonprofit organization that advocates for plant-based nutrition. No other disclosures were reported.
Source: JAMA Network Open
