The 5 biggest mistakes stopping your weight loss success are: 1) having no goals, 2) not measuring your current state, 3) lacking a tailored plan, 4) failing to take action, and 5) not evaluating your progress. Tony McCarthy is a female physique coach who helps clients overcome these mistakes by uncovering goals, doing in-depth assessments, creating personalized plans, keeping clients accountable, and regularly re-evaluating results. His clients now maintain their physiques without struggle and have increased confidence and energy in their lives.