To rule out the possibility that  some other factor caused weight loss, we would need to compare  these participants to a group who didn’t eat breakfast  before the study and continued to skip it during the study.
Para descartar la posibilidad de que otros factores causaran la pérdida de peso, tendríamos que comparar a estos participantes con otras personas que no desayunaran antes del estudio y que continuaran sin desayunar durante el estudio.