McGuire is currently head of Glanbia Performance Nutrition (GPN), which produces sports nutrition products and brands such as SlimFast. He joined Glanbia in 2003 and has held a range of senior leadership roles across the group.
Glanbia also upgraded its full-year guidance on Wednesday to growth of between 12% and 15% in adjusted earnings per share (EPS), reflecting an improved outlook at GPN.
(Reporting by Padraic Halpin; editing by Jason Neely)