So, maybe it's a little judgemental to dismiss Ms. Hari on the basis that she doesn't have a doctorate in food and nutrition, what if she has since striven to educate herself and now has an excellent grounding in science?
Unfortunately this doesn't appear to the the case, as many of her claims would make a Year 10 science class slam their heads in their textbooks. A favourite tagline of hers is the assertion that “There is just no acceptable level of any chemical to ingest, ever”, which should immediately ring alarm bells, as any scientist will tell you, everything is chemicals. Water, bleach, vitamin C, diamonds and even kale smoothies (gasp) are made of chemicals.
The most widely circulated example of this scientific ignorance is her now infamous advice as to how to stay healthy on an aeroplane (or "airplane" if it makes the Americans more comfortable).
When your body is in the air, at a seriously high altitude, your body under goes [sic] some serious pressure. Just think about it – Airplanes thrive in places we don’t. You are traveling in a pressurized cabin, and when your body is pressurized, it gets really compressed!
Or even this amazingly weird assertion:
The air that is pumped in isn’t pure oxygen either, it’s mixed with nitrogen, sometimes almost at 50%
Now, even the most gormless youth in that aforementioned Year 10 science class will be able to tell you that nitrogen makes up about 78% of the Earth's atmosphere, they might even tell you that breathing pure oxygen, particularly under high pressure, is potentially dangerous. You needn't worry, however, as the air pressure in cabins is actually lower than at sea level.
Even though this is quite an old example, and one that Vani has tried (unsuccessfully) to expunge from the internet, it demonstrates that there isn't even a little bit of scientific grounding there. Even the briefest of google searches, let alone a science qualification, will give you all of the information you need on the subject, or even just knowing why sealed containers expand on an aeroplane (hint: it's the difference in atmospheric pressure).
But instead, Foodie Bae here is working off, I don't know, instinct? Old wives tales? It's hard to tell, because it is literally the opposite of fact, whatever it is.