BMI (Body Mass Index) is commonly used in the health and fitness industry as a quick screening tool to categorize individuals based on their weight in relation to their height. While it provides a useful general guideline for assessing body composition, it does not differentiate between fat and muscle mass, leading to potential misclassifications. Despite these limitations, BMI can help identify individuals at risk of overweight and obesity-related conditions. It's vital for healthcare professionals to use BMI along with other assessments to provide a comprehensive view of health.