Mary Catherine Halphen is a registered dietitian in Baton Rouge, Louisiana. She attended Louisiana State University for her undergraduate studies, where she was an active member of the Alpha Eta chapter of Phi Mu Fraternity and also served as chapter president of the school's Student Dietetics Association. She graduated magna cum laude from Louisiana State University in 2018.

During her time at Louisiana State University, Mary Catherine was a performance nutrition intern and worked with over 300 student athletes. She completed a dietetic internship at Vanderbilt University Medical Center in Nashville, Tennessee. Her capstone experience was focused on general pediatrics. Mary Catherine is an active member of the Academy of Nutrition and Dietetics. She currently helps patients at Ochsner Medical Complex - The Grove where she supports the bariatric surgery department.