Step 1. Divide your body weight by 2.2 to calculate your weight in kilograms.
Example: Personal weight is 175 lb. 175/2.2 = 79.5 kilograms.
Step 2. Current scientific research suggests that gym trained athletes need close
to 3 grams of protein per each kilogram of body weight (The US RDA is
1gm/kg) to maintain positive nitrogen balance and muscle growth. Multiply
your kilogram weight by 3. Example: Kilogram weight is 79.5. 79.5 x 3 =
238.5 grams of protein needed.
Step 3. Multiply your grams of protein needed by 3.9 which will give you the needed
protein calories (1 gram of protein = 3.9 calories). Example: 238.5 x 3.9 =
930 calories from protein needed.
Step 4. Current scientific research suggests that a gym trained athlete wishing to
gain optimal lean tissue mass should have a diet comprising 70%
carbohydrates, 25% protein and 5% fat. Multiply the protein calories needed
by 4 to arrive at the total number of calories you need to consume if you are
attempting to eat optimally. Example: 930 x 4 = 3720 total calories needed.
Result: The 175 lb. gym trained athlete will need a diet containing 3,720 total
calories of which 930 calories (238.5 grams) should be protein. If your diet
falls short of these numbers you will not develop muscle as quickly as you
could if your diet was optimal.
Note: The less hard you train, the less total grams of protein you need. Light training athletes can achieve good results with 2 grams of protein per kilogram of body weight.