Children who eat a vegetarian diet have similar measures of growth and nutrition compared to those who eat meat, according to a new Canadian study, but researchers have a key recommendation for followers of such a diet.

The study, conducted by researchers at St. Michael's Hospital of Unity Health Toronto, also found that children with a vegetarian diet had higher odds of becoming underweight. Researchers say this highlights the need for "careful dietary planning" for children who eat a vegetarian diet.

The findings were published Monday in peer-reviewed medical journal Pediatrics.

Dr. Jonathon Maguire, lead author of the study and a pediatrician at St. Michael’s Hospital of Unity Health Toronto, says the findings come as more Canadians choose to limit the amount of meat they consume.

In 2019, Canada's Food Guide was updated to account for the change, including recommendations on incorporating plant-based proteins such as beans and tofu into one's diet, instead of meat.

"Over the last 20 years we have seen growing popularity of plant-based diets and a changing food environment with more access to plant-based alternatives, however we have not seen research into the nutritional outcomes of children following vegetarian diets in Canada," Maguire said in a news release.

According to the study, researchers looked at data collected from 8,907 children aged six months to eight years old, between 2008 and 2019. The children were all participants of the TARGet Kids! cohort study, which was funded by the Canadian Institutes of Health Research, St. Michael's Hospital Foundation, and SickKids Foundation.

The participants were categorized by vegetarian status, which the study defines as "a dietary pattern that excludes meat," or non-vegetarian status.

The study found that children on a vegetarian diet had "similar mean" body mass index (BMI), height, iron, vitamin D and cholesterol levels as the group consuming meat.

According to researchers, the findings also showed that those who ate vegetarian had almost two-fold higher odds of being underweight, defined as being below the third percentile for BMI.

The study says there was no evidence of an association vegetarian diet in kids with obesity or being overweight.

Researchers say underweight is an indicator of undernutrition, which results from an insufficient intake of energy and nutrients to meet an individual's needs to maintain good health.

With this in mind, the researchers say it is important for children who eat a vegetarian diet to have access to health-care providers who can offer growth-monitoring, education and guidance to support their nutrition.

Despite the findings, researchers did not assess the specific foods that made up the vegetarian diets, and say the quality of individual diets "may be quite important to growth and nutritional outcomes."

The study's authors say more research is needed to examine the composition of vegetarian diets in childhood, as well as growth and nutrition outcomes among kids who follow a vegan diet, which excludes meat- and animal-derived products, such as dairy and eggs.

While international guidelines and previous studies on the relationship between vegetarian diets and childhood growth differ, Maguire says the study's findings show a meatless diet is nutritionally safe for children.

"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; however, few studies have evaluated the impact of vegetarian diets on childhood growth and nutritional status," he said in the release.

"Vegetarian diets appear to be appropriate for most children."