Ultra Lean Does Not Necessarily Mean Ultra Healthy
This is another example of a certain 'lean look' being used as evidence of optimal health. We could also replace the word Vegan with many other categories of food choice including Paleo.
There are many ways you can achieve this look, it doesn't mean it's healthy and it is often only maintained in the short term. Ultra-low body fat should not be encouraged as an ideal, especially when health usually has to be comprised to get there (especially for women) and what are the children doing to look that way?
Focus on health!