A white South Carolina man who managed a buffet restaurant near Myrtle Beach admitted in federal court this week that he had beaten and verbally abused an intellectually disabled black cook, forcing him to work over 100 hours a week without pay for about five years, according to the Justice Department.

In pleading guilty to one count of forced labor on Monday, the defendant, Bobby Paul Edwards, 53, said that he had used violence, threats, isolation and intimidation against the victim, John Christopher Smith — or “JCS,” as he is identified in court documents.

Mr. Edwards, who could face up to 20 years in prison when he is sentenced, admitted that while he was in charge, from 2009 to 2014, he beat Mr. Smith with a belt, punched him, hit him with pots and pans and burned Mr. Smith’s bare neck with hot tongs, according to a Justice Department statement released on Tuesday. He also used abusive language and racial epithets against Mr. Smith.

Mr. Smith, who is around 40 years old, had worked at J&J Cafeteria in Conway, S.C., since he was 12, the Justice Department said, and feared losing his job.