How much protein do we need?
Our protein needs depend on our age, size, and activity level. The standard method used by nutritionists to estimate our minimum daily protein requirement is to multiply the body weight in kilograms by .8, or weight in pounds by .37. This is the number of grams of protein that should be the daily minimum. According to this method, a person weighing 150 lbs. should eat 55 grams of protein per day, a 200-pound person should get 74 grams, and a 250-pound person should eat 92 grams.
Another way to compute protein needs has to do with lean body mass. This method is discussed in the Zone Diet and Protein Power books.
Do people who exercise need more protein?
Although it is controversial, there is evidence that people engaging in endurance exercise (such as long distance running) or heavy resistance exercise (such as body building) can benefit from additional protein in their diets. One prominent researcher in the field recommends 1.2 to 1.4 grams per kilogram of body weight per day for endurance exercisers and 1.7 to 1.8 grams per kg per day for heavy strength training.