If someone wants to know more details: Jains who eat leafy vegetables avoid even them during the Paryushan.
All logic of eating which food and which food item not to be eaten is science based.
The basic principles is non-violence and how one can minimise the violence in their life. Hence, tiers are made for classifying life based on number of senses. Seeds typically have only 1 sense, plants have 2-3 sense, animals and humans have 5 senses. Higher the number of senses, the more evolved the life form, hence one needs to minimise/remove the intake of higher number of senses life forms.