Fecal matter would improve its nutritional value.
Not so in Texas at least in Brazoria County the prison food isn't bad. In Texas they are called 'prison farms'. The inmates grow their own food unless this has changed in the last few years. My county preceint voted at the Retrieve Prison Farm in the employees recreation building. I was an election judge for about 7 years and the prisoners brought food from their kitchen to us on election day. Fresh vegetables and home grown meat. The steaks were cut a little thin would be my only complaint.They even brought coffee and cookies for the voters. It never made me sick either.