To date NO scientific evidence has shown a constant, linear increase in muscle mass or performance related to the ingestion of protein. Thus chronic intake of protein (more than 30% of total caloric intake) does not equate to increased fat-free mass. Generally, 1 - 2.0 gm of protein per kg/wt is sufficient for athletes and exercisers depending on goal, activity, protein source, and total caloric intake.
Protein use greater than 2.5 times the RDA (recommended daily allowance) range of 15 - 30% of total caloric intake can have several negative effects, two of which are:
- Calcium depletion - for every gram of protein consumed above tissue maintenance, between 1 and 1.5 mg of calcium is excreted.
- Fluid imbalance - protein requires approximately 7 times the water for metabolism than carbohydrate or fat.
Protein supplements are a convenient and timely way to supply the body with the much needed nutrients it needs to help recover after a hard workout. But the bulk of dietary protein needs should be satisfied by healthy food items. Also, the combination of protein supplements and natural food sources of protein should still not exceed 30% of one's daily total caloric intake.