+1 for freshness

'real' food has 'bio-sensor' ... you can tell just by looking, that a fruit/veggie is bad

it's much harder to 'sense' that in processed food

i find that fruit/veg is harder to fool with, maybe having to do with its low price (not much incentive to cheat)

in my country we got rotten meats cleaned with formaldehyde and then soaked in fresh blood to be sold along with fresh meats ... such thing is unheard of in veg/fruit (groceries can wax to prevent, but once fruit/veg is rotten, it's hard to 'rejuvinate')

being vegetarian leads to simpler life, no worries about mad cow, avian flu, etc