Bob Harper is an American fitness trainer, author, and television personality best known for his role as a coach on the reality TV show The Biggest Loser. He has gained recognition for his motivational approach to fitness and healthy living, helping contestants transform their lives through exercise and nutrition. In addition to his television career, Harper has authored several books on health and wellness, sharing his expertise on fitness routines and healthy eating. He is also known for his advocacy of a plant-based diet and has appeared in various fitness-related media, promoting a balanced lifestyle.