Weight training contributes to fat loss primarily through the development of lean muscle mass, which increases the body's overall basal metabolic rate (BMR). This means that even at rest, individuals with greater muscle mass burn more calories. Additionally, engaging in resistance training has an afterburn effect, leading to increased calorie expenditure post-workout as the body works to repair and rebuild muscle tissue. Coupled with proper nutrition, weight training can effectively reduce body fat percentages while promoting strength and metabolic health, making it a key component of any fitness regime focused on fat loss.