Largest study of its kind highlights benefits – and risks – of plant-based diets in children

Vegetarian and vegan diets can support healthy growth when carefully planned with appropriate supplementation, finds a major new meta-analysis – the most comprehensive study to-date of plant-based diets in children.

A team of researchers, from Italy, USA and Australia, analysed data from over 48,000 children and adolescents worldwide who followed different dietary patterns, examining health outcomes, growth and nutritional adequacy. They found that vegan and vegetarian diets can be nutrient-rich and support healthy growth, but also carry a risk of deficiencies if key nutrients are not obtained through fortified foods or supplements.

The peer-reviewed study, published in Critical Reviews in Food Science and Nutrition, also suggests that plant-based diets may offer additional health benefits for children – including improved cardiovascular risk profiles – compared with omnivorous diets that include meat, fish and other animal-derived foods.

This large meta-analysis is the most comprehensive study to date of plant-based diets in children under 18 years of age, examining data from 59 studies across 18 countries. It compared lacto-ovo-vegetarian (which include dairy products and eggs, but exclude meat, fish and poultry) and vegan diets (which exclude all animal-derived foods) with omnivorous diets across a wide range of nutritional and health outcomes in 7,280 lacto-ovo-vegetarians, 1,289 vegans and 40,059 omnivores.

The study found that vegetarian children consumed more fibre, iron, folate, vitamin C and magnesium than omnivores, but they had lower intakes of energy, protein, fat, vitamin B12 and zinc. While evidence on vegan diets was more limited, similar patterns emerged.

“Notably, vitamin B12 didn't reach adequate levels without supplementation or fortified foods, and calcium, iodine and zinc intakes were often at the lower end of recommended ranges, making them important nutrients to consider for children on plant-based diets,” explains the study co-author Dr Jeannette Beasley, an Associate Professor in the Departments of Nutrition and Food Studies and Medicine at New York University.

“Vegan children, in particular, had especially low calcium intake.”

Health benefits

Despite these risks, both vegan and vegetarian children displayed more favourable cardiovascular health profiles than omnivores, with lower total and low-density lipoprotein (LDL) cholesterol – the “unhealthy” form of cholesterol.

Growth and body composition measures indicated that children on plant-based diets tended to be leaner than omnivores: vegetarian children were slightly shorter and lighter, with lower body mass index (BMI), fat mass and bone mineral content. Vegan children also had shorter stature and lower BMI scores.

“Our analysis of current evidence suggests that well-planned and appropriately supplemented vegetarian and vegan diets can meet nutritional requirements and support healthy growth in children,” states lead-author Dr Monica Dinu, who focuses on exploring how nutrition shapes health and well-being at the Department of Experimental and Clinical Medicine, at the University of Florence, in Italy.

Parents: take an informed approach

Plant based diets remain entirely achievable for children and can offer environmental advantages as well as health benefits. The authors stress that families should not be discouraged from choosing vegetarian or vegan diets for ethical, environmental or health reasons. Instead, they recommend that parents approach these diets with informed planning and, where possible, seek support from clinicians such as dietitians and paediatric health professionals. With attention to a few key nutrients, these diets can fully meet children’s needs during periods of rapid growth while reducing nutritional risks.

“We hope these findings offer clearer guidance on both the benefits and potential risks of plant-based diets, helping the growing number of parents choosing these diets for health, ethical or environmental reasons,” Dr Dinu adds.

More research needed, but balance is key

The authors also emphasise the need for clear, evidence-based guidance to support families with planning healthy plant-based diets for children, who may have higher nutritional needs during periods of rapid growth and development.

However, the researchers caution that these results are limited by the cross-sectional design of most included studies, variability in methods and populations, and challenges in accurately assessing children’s dietary intake.

“In conclusion,” says fellow co-author Dr Wolfgang Marx, from the Food & Mood Centre, at Deakin University, Australia, “while well-planned vegetarian and vegan diets are nutritionally adequate and beneficial for adults, there is far less clarity about their suitability for children – leading to inconsistent or even conflicting advice for parents.

“Our findings suggest that a balanced approach is essential, with families paying close attention to certain nutrients – particularly vitamin B12, calcium, iodine, iron and zinc – to ensure their children get everything they need to thrive.”

Reference:

Lotti, S., Panizza, G., Martini, D., Marx, W., Beasley, J. M., Colombini, B., & Dinu, M. (2025). Lacto-ovo-vegetarian and vegan diets in children and adolescents: a systematic review and meta-analysis of nutritional and health outcomes. Critical Reviews in Food Science and Nutrition, 1–21. https://doi.org/10.1080/10408398.2025.2572983