Final answer:
A healthy dietary recommendation for a 17-year-old male aiming to add muscle mass to accompany his resistance training would be to ensure an adequate intake of protein, crucial for muscle repair and growth, while not neglecting moderate fat and proper carbohydrate intake.
Step-by-step explanation:
To support his resistance training program and goal of adding muscle mass, the healthy dietary recommendation for a 17-year-old male would be D. Adequate protein intake. Protein is vital for metabolic reactions that generate ATP, which is heavily relied upon during exercise. Athletes, especially those in training, need to consume 1.2 to 2.0 g/kg/day of proteins to aid in muscle maintenance, growth, and repair.
Additionally, moderate fat intake should be maintained as it provides energy, essential fatty acids, and helps with the absorption of fat-soluble vitamins. While high carbohydrate intake is essential for daily energy needs and especially important for athletes due to carbohydrates being a major fuel source during exercise, it is the adequate protein intake that is specifically important for the client's goal of muscle mass gain.