In a separate action in July, Nichols asked his trial judge to suspend his $14.5 million restitution order.
In a supplemental filing Thursday, he explained the restitution order stands in the way of the fresh diet he desires.
He explained to the judge the prison allows him to spend only $25 a month on commissary purchases since he cannot make scheduled payments. He wrote that's not enough for him to buy the food he wants.
Nichols also asked for less-restrictive confinement. He is locked in his cell 22 hours most days.
Nichols wrote that, whenever possible, he buys for his three children Christian-based materials, such as books on the Bible, psychology and money management. He wrote he buys the materials "to help guide his children since he is not able to be with them to instill godly values into their lives."
A prison spokesman, commenting on Nichols' food complaints, said the facility provides inmates, including Nichols, with nutritious meals that meet dietary needs.