A New York City private equity firm said it acquired theSouth Beach Diet brand in partnership with its founder, Dr. Arthur Agatston.

MidOcean Partnerssaid it plans to develop new and improved South Beach Diet branded foods, including high protein and high fiber cereal and diet bars. Likewise, officials say they will take the brand  into  new health and wellness food categories aimed at the brand's loyal consumer base. They said South Beach Diet will be headquartered in Bonita Springs, Fla.

Officials says there are an estimated 23 million copies of Dr. Agatston'sThe South Beach Diet -- and its companion books -- in worldwide circulation. A new book, "The South Beach Wake-Up Call," is scheduled for release in October 2011, officials said.

MidOcean said it named Elise Donahue, a 30-year CPG veteran, as CEO of South Beach Diet. Donahue previously served with MidOcean as president and chief operating officer of Prestige Brands, International, a former MidOcean portfolio company. She has also served as board member for various MidOcean portfolio companies.

"Our exclusive discussions with South Beach Diet's founders and owners, Dr. and Mrs. Agatston, have led to this very exciting opportunity to acquire an iconic and highly influential diet and lifestyle brand and we are pleased that we have been entrusted as their partners to help it continue to prosper," said David Basto, a MidOcean managing director.  "Our previous success in the diet and wellness sector with Jenny Craig and Vitaquest, combined with the expertise of our operating executives, will further strengthen South Beach Diet and help accelerate its growth and profitability."

Said Donahue, "The South Beach Diet brand is a valuable and sustained health and wellness franchise and we have a strong management team in place with a detailed execution plan and a clear path to bringing healthy and delicious South Beach Diet foods to stores nationwide.  We look forward to our partnership with Dr. and Mrs. Agatston to grow this highly attractive health-conscious brand."