Vegetarian parents, especially from India, living in the Western world, do wonder if their kids are missing out on something by not eating meat. A perfect proxy of complete nutrition is height.
Here are some graphs for parents to decide.
Height vs Vegetarianism in India
The two graphs below show that the tallest male heights in India have very little correlation with meat consumption. The tallest males, statistically, are in Punjab (67% vegetarian), J&K (31% vegetarian), Kerala (3% vegetarian), and Haryana (70% vegetarian). In fact, some of the highest meat-consuming states, like Andhra and Bengal, are the shortest. And that is likely due to a lack of prosperity leading to malnutrition.
Once the people are prosperous enough (e.g., J&K, Kerala, Haryana, and Punjab) and have solved malnutrition, the meat seems to offer very little in terms of height gain. Now, of course, there are 100s of health parameters, but stunted height is probably the most visible indication of malnutrition. This would have settled the question of meat consumption at least for the vegetarian parents.
Male height vs vegetarianism in India
Height growth over time
However, when one looks at the height changes over time, a different picture emerges. The growth in male height in vegetarian Haryana and Punjab has stalled. While in Kerala and Tamil Nadu have been growing steadily.
Kerala and Tamil Nadu have made huge gains in male height
Does that mean that meat consumption is the reason for the height growth in Kerala and Tamil Nadu?
Well, for that, we can look at a different global graph.
Height growth: China vs. the Netherlands
China and Netherlands both have at most 2-5% vegetarian population.
Male height across countries over time
The graph shows that the height growth in the Netherlands has plateaued at its maximum over the last 20+ years while the height growth in China has been remarkable.
That should not be a surprise, as China suffered major famines and malnutrition episodes in the 1950s and 1960s under Mao’s rule.
While males in the Netherlands have probably attained their maximum height potential.
So, now back to Kerala and Tamil Nadu. South India suffered major famines under British rule.
And Haryana and Punjab benefited from the Indian government’s focus on the Green Revolution in the 1960s and 1970s. While the overuse of pesticides in Haryana and Punjab has led to a rise in diseases like cancer which almost certainly stalled the height growth in those states.
Over time, though, Kerala became prosperous due to its Gulf-remittance-based economy and Tamil Nadu due to industrialization, which fixed the malnutrition problem in those states.
Conclusion
Vegetarian children are not missing out on height growth as long as they are getting proper nutrition.