A new study with infants reveals that those from vegetarian households follow growth trajectories nearly identical to their omnivorous peers by the age of 2.
A landmark study published in JAMA Network Openfound plant-based diets do not hinder early physical development compared to meat-inclusive diets. These findings provide long-awaited reassurance for primary care physicians and pediatricians managing infants.1,2
This study of more than 1.1 million infants, led by investigators from Ben-Gurion University of the Negev (BGU) and the Nutrition Division of the Israeli Ministry of Health from 2014-2023, tracked about 70% of the children in the country for key development markers, including weight, length, and head circumference. Investigators found the mean differences between groups to be clinically minor (WHO z-score <0.2). When adjusted for birth weight, these differences diminished further, suggesting that dietary patterns do not compromise fundamental physical development in developed countries.
The breakdown of the participants was the following: 98.5% of the infants were from omnivorous households; 0.3% from vegan households, and 1.2% from vegetarian households.
The research results revealed a few key insights:
Researches provide several limitations in this study some of which include coverage limited to municipality-operated FCCs, most visits occurred during the first year of life with 37% of children lacking measurements at age 24 months or older, there was a single caregiver-reported household measure for dietary pattern which did not capture infant intake and definitions of vegan and vegetarian were not standardized.
Key Facts
Primary Care’s Guidance on Infants with a Vegetarian Diet
Patient Care: The data shows that by 24 months, stunting and underweight prevalence narrowed significantly across all groups. Is this "catch-up" growth a result of physiological adaptation or external interventions like nutritional counseling?
Karem Avital, RD, MPH: This is an excellent question, but unfortunately our study design cannot distinguish between physiological adaptation and the effects of external interventions like nutritional counseling. We didn't collect data on whether families received nutritional guidance or made dietary modifications during this period.
What we can say is that the convergence occurred within the context of Israel's universal healthcare system, where all families have access to routine well-child visits and can nutritional support when needed. Whether the similar growth trajectories reflect adequate baseline nutrition, natural catch-up growth, or the impact of clinical monitoring and counseling, or some combination, remains unclear from our data.
I think the key takeaway is that in a developed country setting with food security and access to healthcare, infants from vegan and vegetarian households achieved growth outcomes comparable to their omnivorous peers by age two. This suggests that under these conditions, well-planned plant-based diets can support normal infant growth, though we cannot specify which factors were most critical to this outcome.
Patient Care: Birth weight was found to be a significant mediator of postnatal growth differences. How should clinicians distinguish between growth delays caused by maternal nutrition during gestation versus postnatal dietary patterns?
Karem Avital, RD, MPH: When a child is born small (whether low birth weight [<2.5 kg] or small for gestational age [SGA]) this reflects maternal factors including nutrition and related factors such as BMI. In these cases, careful monitoring is warranted to ensure the child stays on their growth curve or achieves appropriate catch-up growth.
In contrast, if a child begins to deviate from their established growth curve after around 6 months of age - when transitioning from breast milk or formula to solid foods, this is when we need to carefully evaluate whether the diet is meeting the child's nutritional needs at that developmental stage.
In our study, we did not observe signs of major deviations in the growth curves of children from vegan or vegetarian households, suggesting that at least up to age 2 years, these family dietary patterns do not appear to have clinically significant association with growth when compared to omnivorous diets.
However, as I mentioned in the previous question, growth assessment should always be individualized and interpreted within the broader context of a child's longitudinal growth trajectory, overall health status, and nutritional intake, rather than relying solely on population-level statistical differences.
Patient Care: What specific components should a "well-planned" vegan diet include to ensure it meets an infant’s high metabolic demands? How can clinicians help parents distinguish between "healthy" and "unhealthy" vegan dietary patterns?
Karem Avital, RD, MPH: A well-planned vegan diet for infants should include good sources of protein and essential nutrients. Key components include legumes (beans, lentils, chickpeas), tofu, and nut and seed spreads such as tahini, almond butter, and peanut butter, preferably with no added sugar or other ingredients beyond the nuts themselves.
It's also important to ensure adequate intake of key nutrients that require special attention in plant-based diets, such as vitamin B12 (through supplements), iron, zinc, calcium, and omega-3 fatty acids.
Regarding distinguishing healthy from unhealthy patterns, this is particularly important given the rising availability of ultra-processed vegan substitute products. Clinicians should guide parents to prefer a diet based on whole plant foods and minimize consumption of highly processed foods as much as possible. This guidance aligns with recommendations for all children regardless of dietary pattern. The focus should be on whole grains, vegetables, fruits, legumes, nuts, and seeds rather than processed vegan alternatives.
Referring families to a registered dietitian who is knowledgeable about plant-based nutrition can be especially valuable to ensure the diet is well-balanced and meets the infant's nutritional needs during this critical period of growth.
Patient Care: Based on these findings, how should a pediatrician’s counseling strategy change when a parent expresses the intent to raise their child on a vegan diet from birth?
Karem Avital, RD, MPH: Based on these findings, I would suggest several key elements for pediatricians counseling families choosing vegan diets:
First, prenatal counseling is important. Referring pregnant vegan women to a registered dietitian, with emphasis on adequate intake of protein, vitamin B12, vitamin D, iron, calcium, iodine, and omega-3, can help support optimal fetal growth and development.
Second, emphasize the importance of regular growth monitoring. Parents from vegan and vegetarian families should understand the value of attending all scheduled well-child visits, as this monitoring allows early detection of any concerns such as underweight or growth delays and enables intervention when needed.
Third, support and encourage breastfeeding. Our data shows that vegan and vegetarian mothers breastfeed at higher rates and for longer durations, which is beneficial for both mothers and infants. This positive health behavior should be encouraged.
Finally, and perhaps most importantly, provide balanced reassurance. It's important to reassure parents who have chosen a vegan or vegetarian lifestyle that infants can grow and develop normally with these dietary patterns, as our findings suggest. This reassurance should be coupled with guidance on ensuring a well-planned diet based on whole plant foods and the importance of appropriate supplementation and professional nutritional support when needed.
Study investigator Karem Avital, RD, MPH, a public health nutritionist associated with the Department of Epidemiology, Biostatistics, and Community Health Sciences at Ben-Gurion University of the Negev in Israel sat down with Patient Care Online and discussed the findings.
Editor’s Note: The above transcript has been lightly edited for grammar and clarity.
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