Kids with vegetarian diets record similar growth, nutrition measures as those who eat meat: Study

A study of nearly 9,000 children has found those who eat a vegetarian diet had similar measures of growth and nutrition compared to children who eat meat.

The study, led by researchers at the University of Toronto and St. Michael’s Hospital of Unity Health Toronto, also found that children with a vegetarian diet had higher odds of underweight status – emphasizing the need for special care when planning the diets of vegetarian kids.

The findings, published in the journal Pediatrics, come as a shift to consuming plant-based diets grows in Canada. In 2019, updates to Canada’s Food Guide urged Canadians to embrace plant-based proteins, such as beans and tofu, instead of meat.

Professor Jonathon Maguire (photo courtesy of St. Michael's Hospital, Unity Health Toronto)

“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,” said Jonathon Maguire, principal investigator on the study who is a professor in U of T’s department of pediatrics in the Temerty Faculty of Medicine and a pediatrician at St. Michael’s Hospital.

“This study demonstrates that Canadian children following vegetarian diets had similar growth and biochemical measures of nutrition compared to children consuming non-vegetarian diets,” said Maguire, who is also a scientist at U of T’s Joannah & Brian Lawson Centre for Child Nutrition. “Vegetarian diet was associated with higher odds of underweight weight status, underscoring the need for careful dietary planning for children with underweight when considering vegetarian diets.”

The researchers evaluated 8,907 children aged six months to eight years. The children were all participants of the TARGet Kids! cohort study and data was collected between 2008 and 2019. Participants were categorized by vegetarian status – defined as a dietary pattern that excludes meat – or non-vegetarian status.

The team found children who had a vegetarian diet had similar mean body mass index (BMI), height, iron, vitamin D and cholesterol levels compared to those who consumed meat. The findings showed evidence that children with a vegetarian diet had almost two-fold higher odds of having underweight, which is defined as below the third percentile for BMI. There was no evidence of an association with overweight or obesity.

Underweight is an indicator of undernutrition, and may be a sign that the quality of the child’s diet is not meeting the child’s nutritional needs to support normal growth. For children who eat a vegetarian diet, the researchers emphasized access to health-care providers who can provide growth monitoring, education and guidance to support their growth and nutrition.

International guidelines about vegetarian diet in infancy and childhood have differing recommendations, and past studies that have evaluated the relationship between vegetarian diet and childhood growth and nutritional status have had conflicting findings.

“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. Vegetarian diets appear to be appropriate for most children,” said Maguire, who is also a scientist at the MAP Centre for Urban Health Solutions at St. Michael’s Hospital.

A limitation of the study is that researchers did not assess the quality of the vegetarian diets. The researchers note that vegetarian diets come in many forms and the quality of the individual diet may be quite important to growth and nutritional outcomes. The authors say further research is needed to examine the quality of vegetarian diets in childhood, as well as growth and nutrition outcomes among children following a vegan diet, which excludes meat and animal derived products such as dairy, eggs and honey.

The study was funded by the Canadian Institutes of Health Research (CIHR), St. Michael’s Hospital Foundation and SickKids Foundation.

A version of this story was first published on the website of St. Michael's Hospital, Unity Health Toronto.