If you take too much protein, say you weigh 150 pounds and take 300 grams of protein a day - your body will not be able to process all the protein into amino acids. What your body can not use will have to be excreted as a waste product. This means your kidney and liver will be doing a lot of work just to get the excess protein out of your body. While this will not cause any major problems over a short period of time - you would not want to be overworking your kidney and liver over the course of several years.
*The latest study from the International Journal of Sports Nutrition
says that people involved in strength training should get 1.6 - 1.7 grams protein per kilogram (2.2 pounds) of bodyweight per day. That is .7 grams per pound. Therefore, a 200 lb man (200 * .7) would need 140 grams of protein. Slightly less than the first formula.
As an estimate we figure that you should consume between .7 - .9 grams of protein per pound of body weight. These numbers vary based on the amount of body fat you have. Women have higher body fat than men, so they should be on the lower end of the scale. Here are some examples:
150 pounds = 105 - 135 grams of protein a day
160 pounds = 112 - 144 grams of protein a day
170 pounds = 119 - 153 grams of protein a day
180 pounds = 126 - 162 grams of protein a day
190 pounds = 133 - 171 grams of protein a day
200 pounds = 140 - 180 grams of protein a day
220 pounds = 154 - 198 grams of protein a day
240 pounds = 168 - 216 grams of protein a day
260 pounds = 182 - 234 grams of protein a day