MIAMI — One too many bouts of flatulence and cramping has led a Florida inmate to sue the Department of Corrections, arguing that the prison’s soy-based turkey dogs and sloppy Joes amount to cruel and unusual punishment.

Eric D. Harris, 34, who is serving a life sentence for sexual battery on a child, said the soy in his prison chow is threatening his health by endangering his thyroid and immune system. Florida prisons serve meals with 50 percent soy and 50 percent poultry three times a day, a mixture that costs half as much as using beef and pork, the Department of Corrections says. The cost per meal: $1.70 a day for each inmate. Florida prisons first began serving soy-based meals in 2009.

As an inmate at the Lake Correctional Institution, near Orlando, Mr. Harris, a former paralegal, has few culinary choices. He can eat 100 grams of soy protein a day, use his own money to buy food at the commissary or eat a vegan diet, he said in the lawsuit, which was filed in state court in Tallahassee and which The Orlando Sentinel reported on this week.

Gretl Plessinger, a spokeswoman for the Florida Department of Corrections, said inmates can choose an alternative vegan meal if they do not want soy. “We have a constitutional obligation to feed them healthy, nutritious food, but we don’t have an obligation to feed them beef,” she said.