For some people it's possible, especially those newer to training or just starting a regular routine. The keys are a balanced diet with enough protein, moderate resistance training, and consistent execution. That said, it must be stated clearly that results vary from person to person — not everyone, and not at every stage, can do both at once.
Cina worked toward a muscle-gain goal, adding about 10 lbs over 3 months with products, a balanced diet, and exercise; over the same period Phu lost about 25 lbs of fat and gained about 1 kg of muscle (personal results — individual results vary). Both required systematically arranged nutrition and training, with ongoing follow-up and adjustment.
If you want to address body fat and muscle together, having a coach tailor a plan and follow up usually gives you a clearer sense of direction.