The National Academy of Medicine recommends that adults get a minimum of 0.8 grams of protein for every kilogram of body weight per day, or just over 7 grams for every 20 pounds of body weight.
For a 140-pound person, that means about 50 grams of protein each day.
For a 200-pound person, that means about 70 grams of protein each day.
The National Academy of Medicine also sets a wide range of acceptable protein intake—anywhere from 10% to 35% of calories daily. Beyond that, there’s relatively little solid information on the ideal amount of protein in the diet or the healthiest target for calories contributed by protein.