In England eating beef has been a prestige marker for at least several hundred years[1]. A traditional diet of that type will be more than adequately healthy. What’s hard is getting over ancient superstitions about animals being reincarnated people and then rationalizing that it’s actually healthy for an omnivorous species to abandon eating meat.

Or maybe there’s no reason to believe that a diet that’s healthy for Indians is necessarily healthy for Europeans or vice versa.

[1] https://www.goodreads.com/book/show/6043908-beef-and-liberty