it’s fruits and vegetables. Collectively they are the number one and two sources of all nutritional requirements for the human body
I disagree upto a point
about this. Meat is one of the best sources of Iron, (Heam), it's got aroudn a 15-20% absorption level, which Non Heam doesn't, (5-10% approx).
Plus Fruits and Vegetables are poor for Amino Acids. A Large Broccoli stalk has around 1.5g Protein.
Apart from anything else, things like Legumes, contain Antioxidents and Fruits and vegetables are useful for a good range of nutrients including Antioxidents, but if you had an intake that created a low Amino Acid intake, you could consistently get an essential Amino Acid requirement.
Something which if severe and prolonged, can potentially kill you.
I would actually place Legumes ahead of Fruits and Vegetables in this regard, because they contain Antioxidents, but also a better Amino Acid profile.
Though of course Fruits and Vegetables have their merits.
Cooking can reduce Fat and Carbohydrate content, as well as denaturing Proteins.
Some Fruits and Vegetables are high GI, like Watermelon, (73 approx), Parsnips, (90 approx), and Potato, (varys depending on if it's White, Red or Sweet).
That's just a minor point though. His diet isn't ridiculous, but frankly I wouldn't indulge it, even though it has it's origins based in the dim and distant past and is a relevant style of eating.