Justyna Mizera, MA, is a sports nutritionist, and since 2009 she has balanced over 1,100 diets for athletes in various sports. She works with, among others, 30 world championship medalists and Olympians, but also with obese adults and children. She has competed in body fitness competitions. Author of numerous scientific and popular-science articles. She appears as an expert source for television stations. She also teaches courses in dietetics.