NEW YORK — Charles M. Harper, who in the 1970s and 1980s transformed a faltering food company called ConAgra into a global giant to rival Kraft and Kellogg, and whose own health issues inspired the creation of the brand Healthy Choice, died Saturday at his home in Omaha. He was 88.

His death was confirmed by his daughter Kathleen Wenngatz, who said he had been in gradual decline.

In 1985, when ConAgra’s expansion was in full swing, Mr. Harper had a heart attack and was forced to change his eating habits. That led him to introduce a line of lower-calorie products, which ended up being called Healthy Choice. In part inspired by a turkey chili dish made by Mr. Harper’s wife, Joan, Healthy Choice meals aimed to be tasty as well as healthier. “She was a great cook,’’ Wenngatz said. “He brought that idea to the company.’’

Sales of Healthy Choice took off quickly, and the line is still offered by ConAgra.

“This is a rare case of a CEO coming up with a product that changed the company,’’ said William Leach, who followed ConAgra as a stock analyst when Harper was chief executive.

Later in his career, Mr. Harper was chief executive of RJR Nabisco, the food and tobacco company in which Kohlberg Kravis Roberts, a leveraged buyout firm, had a large stake.

At ConAgra, Mr. Harper oversaw one of the most notable turnarounds in postwar corporate America. He joined ConAgra in 1974 after 20 years at Pillsbury, another food company. ConAgra at the time was suffering losses that had put it close to bankruptcy. Mr. Harper, who was known as Mike, and wore short-sleeved shirts in the dead of winter, became its chief executive in 1976 and was in that post until 1992.

During that period, the company’s sales grew to over $20 billion from $600 million and its stock price rose many times over. Much of the growth came from acquiring scores of companies, a strategy that can come undone without financial discipline. But Mr. Harper told his executives to push uncompromisingly for profits without taking on too much debt.

“He would literally buy anything related to the food business,’’ said Leach, the former analyst. “It got a little stretched, but somehow he made it work.’’

Mr. Harper became chief executive of RJR Nabisco in 1993. Kravis hoped that his skills would revive the company. But Harper struggled, in part because of challenges facing the cigarette business, and he left RJR Nabisco in 1996.

Mr. Harper’s last months at the company were marked by controversy. At RJR’s annual meeting, he suggested that infants who were endangered by their parents’ smoking could crawl out of the room. Mr. Harper later explained that he was exaggerating to make the point that it was up to the parents to protect their children from cigarette smoke.

Charles Michael Harper was born in 1927 in Lansing, Mich. His father, Charles, was a hearing aid salesman, and his mother, the former Alma Anna Michel, helped her husband in that business.

Mr. Harper was an undergraduate at Purdue University and got an MBA at the University of Chicago. He married Joan Bruggema in 1950. She died in 1999.

In addition to his daughter Kathleen, Mr. Harper leaves two other daughters, Elizabeth Murphy and Carolyn Harper; a son, Charles Jr., a neurologist at the Mayo Clinic; 11 grandchildren; and 11 great-grandchildren.