Doctor J - High Protein Diets

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malea jensen 06 August, 2008 10:03:00

Malea Jensen

Doctor J discusses the safety of high protein diets relative to the needs of hard training athletes.

August 7, 2008

by Malea Jensen

High Protein Diets

With so many diets out there, you must be asking yourself what is the right one for you. I have been asked on a number of occasions by patients, friends, and clients alike, about the safety of high protein diets.

Let’s first review the basics about protein. Protein is the first of the major nutrients—carbohydrates and fats being the other two. Anyone engaged in intense physical activity needs protein for growth and repair. Protein is made up of the building blocks called amino acids. There are 22 amino acids in all--13 can be manufactured by the body and are called “non-essential.” The other nine are “essential” amino acids because they cannot be manufactured by the body and must be consumed in the diet.

Not all proteins are alike when it comes to providing amino acids. Complete proteins are those that contain all the essential amino acids in the right proportions. Examples of complete proteins are milk, eggs, meat, fish, and some vegetable products such as soybeans.

Incomplete proteins, on the other hand, are found in grains and vegetables. They are usually low in a particular amino acid, but should not be excluded from the diet. In fact, if you combine two or more sources of incomplete proteins (i.e. cereal with milk) you can obtain a high quality, complete protein.

Although it varies, hard training athletes need approximately 1.2 to 1.6 grams of protein per pound of bodyweight per day to sustain muscular growth and repair. For a 200 pound athlete this means eating 200-250 grams of protein per day in divided meals.

By now, you have heard about bodybuilders consuming upwards to 400-500 grams of protein a day, and you are wondering if that article you read saying that the body can absorb only 25-30 grams of protein every 3 hours is actually on the up and up. And then, you strut into the local GNC to grab a meal replacement shake and the label is packing in 50 grams of protein per serving. What do you do now?

The simple truth is that protein is needed to support muscle growth and recovery. The more protein you eat and the more intense you train, then the bigger and more muscular you will be—assuming this is your goal.

Allow me to put it in a different context to help you understand. Lets say we have an intense training bodybuilder seeking to build as much lean mass as possible. He is training hard and smart and consuming 4-5 meals a day consisting of 30 grams of protein. This equals about 120-150 grams of protein a day. Do you actually think this is going to support a 300-pound bodybuilder still looking to put on some more size? Doubtful!

Take a look at the prevalence of high protein/low carbohydrate diets today. While still controversial in terms of long-term success, in the short-term, people are reducing body fat levels and increasing lean muscle mass. By the way, from a physician’s point of view, there is no conclusive evidence that high protein diets in healthy individuals have any serious negative consequences.

What I would like to do next is to explain the difference between protein “need” and the amount you NEED to grow. First, there is something called nitrogen balance. Nitrogen balance is found by measuring the amount of nitrogen ingested from all protein sources followed by measuring the amount of nitrogen excreted in the urine, feces, and sweat. I realize not many of you will be measuring nitrogen balance, but for purposes of this article, let’s assume we could measure nitrogen ingestion and excretion each day. If the amount of nitrogen excreted is greater than the amount of nitrogen ingested, that person is said to be in “negative” nitrogen balance. At this point, it is safe to assume that the athlete will start to lose muscle mass as the body will start to break down muscle to use the amino acids for fuel.

If, however, the nitrogen ingested is equal to the nitrogen excreted, that person is said to be in nitrogen balance. This athlete is neither shrinking nor growing and perhaps the best term to describe this athlete is to say they have “plateaued.”

Now, if the nitrogen ingested is greater than the amount excreted, the athlete is in a state of “positive” nitrogen balance. Since this athlete is training hardcore, it is assumed that the extra protein in the body will be used by the GROWING muscle tissue!

As you read articles or studies on the topic of high protein diets, it is important to recognize that most of these studies are performed on individuals who are sedentary and it has typically been recommended that sedentary individuals consume 0.8 g of protein per Kg of weight. This equals 0.36 g per pound. This amount will meet “need.”

Where does this leave the hard training athlete? Shrinking! Seriously, though, this is why more studies are being performed on athletes these days. It is generally believed that in order to maintain positive nitrogen balance, athletes do in fact, need 0.8-1.5 g per POUND of bodyweight per day.

To sum it up, the general rule of thumb for hardcore, training athletes (male and female, alike), is consume one gram of protein per pound of bodyweight per day. If after a few weeks, you are not noticing increased muscle size, increased energy, improved recovery, then gradually increase your intake to 1.25 g protein per pound of bodyweight.

Good luck with the diet and let me know how you are doing. For more information do not hesitate to contact me through my website at www.maleajensen.com. Until then, train hard and smart!

Malea Jensen, D.O. is a physician of family and preventative medicine and a competitive national level bodybuilder. She is known at Dr. J and the IronLadyDoc. She received her medical degree from the University of Osteopathic Medicine and Health Sciences, Des Moines, Iowa, and completed a family medicine residency at Iowa Lutheran Hospital, Des Moines, an affiliate of Iowa University School of Medicine. Dr. Jensen is NSCA-CPT certified. She authors health and fitness articles and promotes preventative medicine through community lectures.

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