Protein: power or poison?

Posted on March 9, 2011. Filed under: Nutrition |

Last week I got a comment asking about high protein diets.

Although my blog is in the early stages I feel I should state something before I begin.  I’m not big on anonymous online debates.  I just have better things to do.  I’m always up for a respectful discussion.  But if you feel I am so vehemently wrong you need to overwhelm me with info and logic, know this.

If I don’t know you, I won’t read it.

Nothing personal, I just want to be honest.  If you are still passionate about your case than maybe we can arrange for you to present it in person at a local eatery or smoothie place.  Needless to say, if this transpires, your buying 🙂

OK moving on to the task at hand, protein.

Being a fitness coach I have had many a  . . . dispute with colleagues in the health profession, especially registered dietitians.  The main reason for this is the RDA

For those not familiar RDA stands for “Recommended Dietary Allowance,” the government-recommended daily amounts of protein, vitamins and minerals for healthy adults.

Now according to dietician the RDA for protein is sufficient for all conditions, including those who compete in sports. the current standard by my understanding is 0.8 g/kg (0.36 g/lb) protein per day. So for someone like me who weighs 200 lbs, that’s a mere 72 grams of protein per day. I can eat that in a meal.

Too be fair on the opposite side of the coin we have some extremist there as well

Bodybuilding circles usually advocate 1 g/lb (2.2 g/kg) as a baseline recommendation with others taking this level to 2 g/lb (4.4 g/kg) or sometimes even higher.

Sadly magazines, usually with a vested interest in selling protein powder tend to promote high protein intakes with claims of athletes eating 800-1000 grams protein per day (a level only achievable with supplementation) being claimed by top bodybuilders.  Too be fair this may be true for top bodybuilders, but mainly because of the ‘additional’ supplements they take, that allow them to more efficiently use such high doses.

Usually with clients I recommend anywhere from .5-1 g/lb (1.1-2.2 g/kg)of protein.

My recommendation is based on a few things in both anecdotal and proven

  • It’s easier to maintain a lower caloric intake.  Protein has a greater satiating factor than carbs.  This is very important when dieting down.
  • Most clients I have had when trying to lose fat and maintain muscle do better on higher protein intake.
  • RDA measures speak to avoiding deficiency, not optimization.  For clients or athletes trying to gain size or improve performance I see no reason why they should limit their intake.  and no study has shown reason to either to date.

Now as far as the question posed as to high protein diets being bad for kidneys.  I see no reasonable evidence for this being the case.  The reason being when people speak of a situation where protein intake had an adverse affect, it is usually anecdotal and takes not regard of dietary displacement.

Example, an individual is told they need to up their protein intake.  They develop nutrition tunnel vision and start doing this at the expense of other “non-protein” foods.  Namely fruits and veggies.
Protein is not bad for your kidneys.  At least no worse than anything else if taken in excess.  Water is good for you, chugging a near gallon of water within an hours time, not so good.  Same thing with protein.  A high protein diet has never been proven to harm your kidneys, unless someone already has a specific predisposition or kidney condition.  And trust us, if you have a problem with your kidney it’s usually pretty obvious.  If your fluid, fiber, and nutrient intake is in balance. There is no need for concern.

  • Martin WF et. al. Dietary protein intake and renal function. Nutr Metab (2005) 2: 25.
  • Millward DJ. Optimal intakes of protein in the human diet. Proc Nutr Soc. (1999) 58(2): 403-13.

The thinking behind this ‘warning ‘ comes from something called the Brenner Hypothesis. Basically, it states that all this extra filtration of protein, affects the urine production, and is “hard on the kidneys.” It causes extra work.  but such a viewpoint is more so speculation then proven fact in the case of a healthy body.

Look at it from the other side, asking a tissue to do extra work does not equal ‘damage.’ It does not ‘ruin’ it. Think about your biceps. When you ask it to do extra work does it ruin it? No, it adapts.  Take into consideration studies where the subjects consume 250g of protein a day with no effects to kidney function.  And you’ve got quite the counter argument.

  • Lowery L. Dietary protein safety and strength athletes: running down a dream. NSCA-Wisc Annual Clinic. Oshkosh, WI, Apr. 2009

Now this does not mean just chug shakes and eat steaks till your in an amino coma.   Remember if you focus to hard on getting a certain macronutrient, you will over look the intake of others
Now apparently some believe that too much protein causes calcium loss.  I never bought into this one but since someone brought it up I looked it up.  I got as far as a web search and a quick pop up from WebMD, the headline “High-Protein Diet Could Repair Bone Loss.”

Apparently the confusion arises from isolating protein without looking at the presence of other nutrients.  It is recognized that dietary protein increases acidity of urine, and that the acid load may have an effect on the calcium in your bones.  This is only a problem however, if you are lacking in calcium.

When calcium intake is low, high protein intakes appear to have negative effects on bone health. In contrast, when calcium and vitamin D intake are sufficient, protein intake has a beneficial effect on bone health. So getting in a good dose of calcium either through  dairy foods, or calcium supplements  is crucial for bone health when a high protein intake is being consumed.

  • Dawson-Hughes B. Interaction of dietary calcium and protein in bone health in humans. J Nutr. (2003) 133(3):852S-854S.

Sufficient calcium intake is important regardless, so I see this as a non-issue as long as you are eating in balance.

Ultimately this is why I stand by my .5-1g recommendation.  I find it to be a good balance to work from.  And helps my clients meet their needs as well as accomplish their goals.

Best Health,

Coach W


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One Response to “Protein: power or poison?”

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Nicely written. Thanks for the study references.

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