As a simple rule, aim for 0.8 to 1 gram of protein per pound of body weight spread over 3-4 meals to optimize muscle growth. Consume at least 50% of your intake from whole foods. For a 150-pound person, this equals 120 to 150 grams per day. If you have a high level of body fat, you may want to re-calculate your protein needs based on lean body mass.