Professor Hegarty has B.Sc and M.Sc degrees in Biochemistry and a BA degree in Economics from the National University of Ireland; a Ph.D in Human Nutrition, University of London. He held academic and administrative positions at the University of Minnesota, University of Houston, Michigan State University. Recently he was Dean, College of Food and Agriculture, United Arab Emirates University. He held Adjunct Professor appointments at the University of Guelph and the University of Texas.  He has taken sabbatical leaves to universities in Jamaica, Zimbabwe, Ireland and at Zayed University (UAE).

He is a Fellow of the International Academy of Food Science and Technology. His consultancies include: Abu Dhabi Food Control Authority (ADFCA), WHO/FAO, USAID, USDA, National Institute of Health (USA) and many food companies. Presently he is Team Leader in a USAID-funded project assisting in the establishment of a food safety agency in Egypt. He founded the Institute for Food Laws and Regulations at Michigan State University. Its distance education program has students from over 80 countries; in 2003 it won the American Distance Education Consortium's Excellence Award for Distance Education.