"Can I have too much protein?"
"How much is too much??"
Hmmm..
How come no body asks me that question
about carbs?
I never get that question about bread,
pasta or chocolate...?
And those few beers or chardies that always
seem to find a way in there a few times a week along with the Chinese, Italian,
Indian takeaway...?
But as soon as we start to place our eating
habits under a little more scrutiny, protein becomes the topic of concern,
particularly, "having too much".
Well guess what? You’ve been having too
much for years.
Yep, most Americans & Australians
already consume double the recommended daily allowance as part of their normal
eating[1,2].
What is a high protein intake exactly?
That's where it gets confusing and
inaccurate. The definitions in the scientific literature range from intakes
greater than 15–16 % of total energy or as high as 35% of total calories or
intakes that merely exceed the RDA of 0.8g/kg/day[1,3].
According to an extensive review of the
research by the International Society of Sports Nutrition, “protein intakes of
1.4 – 2.0 g/kg/day for physically active individuals is not only safe, but may
improve the training adaptations to exercise training”[4]. That amount is up to
two and a half times the RDA.
Concerns about a high Protein diet? Most
people consume around double the RDA without knowing it.
More recent long term investigations have
confirmed previous work that is, up to 3.3 grams of protein per kilo of body
weight per day for one year provided no harmful effects on liver and kidney
function - that's over five and a half times the RDA! And it provided no
increase in body fat [3-6].
What happens if I consume more than the
RDA?
Surprisingly, not much... aside from
improve athletic performance and promote healthy aging[1-7]. Increasing protein
intake doesn't appear to increase weight or body fat. Also, no research has
been able to establish a link of any kind that may suggest a particular protein
amount will damage a healthy organ or body.
How much do I need really?
That depends on what you're doing. Probably
the most important finding from contemporary research on this topic is that, a
higher protein intake won't improve your body composition unless you are
engaged in a structured resistance exercise program.
The methods used to help assess protein
requirements are constantly improving, as a result protein recommendations are
increasing for many populations.
If your goals involve improving health and
body composition (more lean tissue & less fat) then the real experts on
this topic - the ones that actually complete the research, suggest 2-3 times the RDA is not only
acceptable, it's highly recommended. Up to 35% of your total daily energy
intake (rather than the out-dated 10-15%) is recognized as safe and effective
[1,7].
Once you start going much higher than that,
there is a risk of not obtaining enough nutrition, fiber and fuel from other
food sources.
One of the true pioneers of great research
on protein requirements, Robert Wolfe and his team, showed clearly when you
consume protein-only meals in a fasted state, a big chunk is simply oxidised
(converted to blood sugar). So going crazy with very high protein intakes at
the expense of other food sources only teaches your body to burn more of it for
fuel - gluconeogenesis is the biochem term for the conversion of several key
amino acids including the BCAAs to glucose when energy intake is too low.
Our physiology cannot be tricked, it's too
clever after around 10,000 years of evolutionary tweaking.
The bottom line is, the methods used in
research to help assess protein requirements are constantly improving, as a
result so are the estimated recommendations for protein needs in many
populations.
For example, the average protein
requirement recommended for women aged above 65 years has increased up to 1.29
grams per kilogram of body weight per day. Another important recommendation is
25-30 gram dose of protein per meal is considered a safe effective strategy
that promotes better health, satiety and loss of unwanted weight in over weight
adults [1].
If most of us already consume around double
the recommended amount - without even knowing it, based on all the information
we have, maybe a much better question is "Where does your protein come
from, in relation to your health status?"
For example, you could be a 5'9,
middle-aged adult with a body mass index (BMI) over 20.
Or you could be the same height, similar
BMI but carry only around 10% body fat from lifting weights for the last 15 or
so years
Your health status will be very different.
The type of protein consumed and the
lifestyle habits of the individuals consuming them is just as important as the
actual amount. That's the distinction the longitudinal research on dietary
protein intakes has failed to make over the last 50 years in relation to
cardiovascular disease, cancers and diabetes.
The good news is, we are starting to see
the data from people that do live that second half of the equation.[1,7]
Dr
Paul Cribb is an award-winning Scientist, Mentor & Coach to leading
Fitness Professionals. Paul is the
creator of mp-body.com the The Metabolic Nutrition
Coaching Systems - the first ever science-based, research-proven, nationally
accredited coaching program.
References
1. Introduction to Protein Summit 2.0:
continued exploration of the impact of high-quality protein on optimal health.
Rodriguez NR. Am J Clin Nutr. 2015 Apr 29.
2. http://mp-body.com/ask_the_dr/carb-delusions
3. A high protein diet (3.4 g/kg/d)
combined with a heavy resistance training program improves body composition in
healthy trained men and women--a follow-up investigation. Antonio J, Ellerbroek
A, Silver T, Orris S, Scheiner M, Gonzalez A, Peacock CA. J Int Soc Sports
Nutr. 2015 Oct 20;12:39.
4. The effects of consuming a high protein
diet (4.4 g/kg/d) on body composition in resistance-trained individuals.
Antonio J, Peacock CA, Ellerbroek A, Fromhoff B, Silver T. J Int Soc Sports
Nutr. 2014 May 12;11:19.
5. The effects of a high protein diet on
indices of health and body composition--a crossover trial in resistance-trained
men. Antonio J, Ellerbroek A, Silver T, Vargas L, Peacock C. J Int Soc Sports
Nutr. 2016 Jan 16;13:3.
6. A High Protein Diet Has No Harmful
Effects: A One-Year Crossover Study in Resistance-Trained Males. Antonio J,
Ellerbroek A, Silver T, Vargas L, Tamayo A, Buehn R, Peacock CA. J Nutr Metab.
2016;2016:9104792. Epub 2016 Oct 11.
7. Protein "requirements" beyond
the RDA: implications for optimizing health. Phillips SM, Chevalier S, Leidy
HJ. Appl Physiol Nutr Metab. 2016 May;41(5):565-72.