The Power of Protein

Next let’s talk protein. Whereas carbs have been well-studied in endurance athletes, protein requirements have been well-studied in strength athletes. The general RDA for protein is 0.8g/kg/day, which most individuals have no difficulty meeting. Using our 125 lb. individual, this equates to 45g or 180 kcals per day (1g protein=4 kcals).

Though the aforementioned position statement lists the protein recommendation for an athlete from 1.2-1.7 g/kg/day, 2.0g/kg/day is often used as an upper limit of normal. Even athletes aiming for 2.0g/kg/day usually have no problem meeting this requirement from whole food sources (113g, 450 kcals for our 125 lb. athlete). In short, most people do NOT require protein shakes/supplements.

Studies examining nitrogen balance in body builders suggest that requirements may be even higher in this population, up to 3g/kg/day. (Nitrogen balance is used as a surrogate of protein availability in research. A net negative nitrogen balance indicates inadequate protein availability for muscle repair). This suggestion is an extreme, however, and is not generalizable to the public because body builders are usually trying to lose weight at a fast rate while maintaining an extremely low body fat percentage.

Overall, there exists a strong consensus across the literature that 2x the RDA (1.6g/kg/day) is advantageous as compared to 1x RDA in maintaining lean body mass during periods of weight training. The ceiling of this benefit seems to stop around 2g/kg/day for the majority of individuals. Additionally, weight loss studies in non-athletes suggest that high protein diets (again 1.2-1.6g/kg/day) may lead to improved satiety and weight management. I also feel obligated to mention that some diets promote that all sources of protein are created equal (lean chicken=bacon). More at a later date but intuitively, no matter how much you may want this to be true, does it make sense?

Key points:

• Athletes require 1.2-2g/kg/day of protein

• Protein is necessary for muscle fiber repair and synthesis

• Protein helps maintain lean body mass while losing weight

• Protein has proven satiety benefits. If looking to lose weight without any specific fitness goals, increasing protein and cutting carbs may help. [Please always discuss your goals with your physician, as this may not be appropriate if you have certain chronic health conditions].

• Protein shakes/supplements are generally not needed (more at a later date)