Is a Vegetarian Diet Safe for My Kid?

I am vegetarian, and so far I’ve raised my son (15 months) vegetarian. My doctor recently told me that the lack of meat might hinder his bone and brain development. Is there data to back that up?
—Julia

This isn’t well supported by data, no. The best review I can find is one that includes 16 studies, published between 1988 and 2015, of children on either vegetarian or vegan diets. Most studies were small, and they looked at a variety of outcomes: weight, biomarkers, vitamins, etc. In general, this is a difficult thing to evaluate — the samples of people who are vegetarian are often quite different from those who eat meat. They tend to be higher-income, for example. Many of the largest studies focus on Seventh Day Adventist communities, who have other differences.

By and large, the data doesn’t indicate significant differences across groups. The vegetarian children tend to weigh slightly less, which could be selection or could reflect the diet. But they aren’t on average shorter, or deficient in vitamins. There isn’t anything that would point to lower brain development.

The one slightly more consistent finding is that the vegetarian children are more likely to be low in iron, or anemic. This is not especially surprising; meat is a common source of iron. There are non-meat iron sources also, but if you do continue with the no-meat diet, you should be aware of the possible need for supplemental iron.

So watch for iron. But you don’t need to make other meals for him.