Early childhood growth, nutritional status did not differ between vegetarians, nonvegetarians

Children who were on a vegetarian diet had comparable measures of growth and nutrition compared with children on a nonvegetarian diet. However, those on a vegetarian diet had higher odds of being underweight, according to a recent study.

“Vegetarian diets are becoming increasingly popular for adults and children ... Although [a] vegetarian diet is presumed to be healthy for children, few studies have evaluated the impact of vegetarian diet on childhood growth and nutritional status,” said the researchers.

Using data from the TARGet Kids!* cohort study in Toronto, Canada, the researchers conducted a longitudinal study involving 8,907 children (mean age 2.2 years, 52.4 percent male), of whom 248 were vegetarians and 8,659 were nonvegetarians at baseline. Overall, 8,794 and 4,673 of the participants with available data on growth and biochemical measurements, respectively, were evaluated. [Pediatrics 2022;149:e2021052598]

At 2.8 years of follow-up, children with or without a vegetarian diet showed similar BMI z-score (zBMI) and height-for-age z-score (zHeight; adjusted mean difference, 0.01; p=0.84 and -0.08; p=0.05, respectively), although higher odds of being underweight was observed among those on a vegetarian diet (odds ratio [OR], 1.87; p=0.007)

On the other hand, there was no association between vegetarian diet and being overweight (OR 1.13; p=0.36) or obese (OR, 0.69; p=0.20).

Results also showed that vegetarian diet was not associated with levels of serum ferritin and 25-hydroxyvitamin (25(OH)D; adjusted mean difference, 1.11; p=0.72 and 1.45; p=0.20, respectively).

“Since the predominant source of iron and vitamin D in most children’s diets is meat and cow’s milk, respectively, we hypothesized that children with [a] vegetarian diet would have lower serum ferritin and 25(OH)D, which we did not find … [and was consistent with previous] several small cross-sectional and prospective cohort studies,” the researchers noted.

There was also no association between vegetarian diet and serum lipids, including non-high-density lipoprotein (HDL) cholesterol, total cholesterol, low-density lipoprotein, HDL, and triglycerides.

Of note, with regard to cow’s milk consumption, those on a vegetarian diet who reported little to no cow’s milk intake had lower serum lipids than those on a nonvegetarian diet, while those with or without a vegetarian diet who consumed the recommended two cups of cow’s milk a day achieved similar serum lipids.

“Guidelines currently differ on the adequacy of vegetarian diet in childhood,” the researchers said. “In this study, we did not find evidence of clinically meaningful differences in growth or biochemical measures of nutrition for children with vegetarian diet.”

“However, vegetarian diet was associated with higher odds of [being] underweight, underscoring the need for careful dietary planning for underweight children when considering vegetarian diets,” they noted.