According to the University of California, Los Angeles, sedentary people need about 0.36 grams of protein per 1 pound of body weight per day. This is the approximate amount of protein that will help you maintain your body’s current muscle mass.As an example, a 150 pound person would need 54 grams of protein per day.This varies depending upon your sex and age, so consult your doctor for a more precise figure. 150 pounds strength-training athlete may need 109 to 122 grams of protein each day. The amount of protein your body needs to maintain your current lean mass and body weight may vary slightly from these guidelines.