Vegetarian kids have similar growth and nutrition as meat-eating children but more likely to be underweight, study finds

• Vegetarian children don't seem to have growth or nutrient deficiencies compared to their peers, per a new study.
• Children on a vegetarian diet had similar levels of nutrients like iron and vitamin D, researchers found.

Vegetarian children have similar levels of nutrition and growth as their meat-eating peers, but may have nearly double the risk of being underweight, suggests a study published May 2 in the journal Pediatrics.

Researchers led by a team from St. Michael's Hospital of Unity Health Toronto looked at data from nearly 9,000 Canadian children between six months and eight years old, comparing their diets to their height, weight, and nutrition.

They found that the 338 children who had followed vegetarian or vegan diets had similar heights, markers of growth, as children who ate meat. Contrary to the researchers' hypothesis, the vegetarians also had comparable levels of nutrients like iron and vitamin D as meat-eaters did, suggesting the vegetarian children were able to get enough in their diets without eating meat.

However, the vegetarian children were nearly twice as likely as meat-eaters to be underweight, based on body mass index, or ratio of weight to height.

Being underweight may indicate a higher risk of malnutrition or a lack of sufficient calories and nutrients necessary for proper growth, according to the authors. However, more research is needed because other lifestyle variables, including physical activity and specific foods in the diet, could play a role in the findings.

The results highlight that careful planning is important when considering how to meet children's nutritional needs on a vegetarian diet, according to Dr. Jonathon Maguire, lead author of the study and a pediatrician at St. Michael's Hospital of Unity Health Toronto.

"Plant-based dietary patterns are recognized as a healthy eating pattern due to increased intake of fruits, vegetables, fiber, whole grains, and reduced saturated fat," Maguire said in a press release. "Vegetarian diets appear to be appropriate for most children."

Plant-based diets can vary widely, so quality matters for health outcomes

One major limitation of the study is that it did not assess the quality of the vegetarian diets, or specific foods, beyond the exclusion of meat.

The healthfulness of a vegetarian diet can vary depending on which foods are included, evidence suggests. Plant-based diets rich in veggies, whole grains, beans, nuts, and fruit are linked to better health outcomes. But many highly-processed foods are also vegetarian, can be high in sugar, salt, and preservatives, and linked to health issues.

A small study from 2021 found that vegetarian children who ate more processed plant-based foods had elevated levels of cholesterol and blood sugar. They also tended to eat fewer foods like vegetables, fruits, nuts, and whole grains, missing out on important vitamins and nutrients like fiber, according to the researchers.

"We are learning that just eating plant-based diets is no guarantee of health, we still need to select healthy foods," Dr. Małgorzata Desmond, first author of that study and researcher at The Children's Memorial Health Institute, said in a press release.

More research is also needed on vegan diets, which cut out meat as well as other animal products like dairy, eggs, and honey.

The same study from 2021 suggested that vegan children may be at higher risk of mineral and vitamin deficiencies such as calcium and B vitamins, which may cause lower bone mass and density. However, vegan children are more likely to have healthy levels of cholesterol and other markers of good heart health, the data suggested.