Protein: The correct portion

Protein, an essential macronutrient, is commonly overconsumed in the American diet. It plays an important role in chemical reactions in the body and builds the body in the form of muscles and tendons. Protein aids satiety and helps build a lean body mass. The problem in the diet of Americans is purely eating too much protein which is a key contribution of the current obesity epidemic. A key to resolving the over consumption of protein would be better education about the role of protein in the diet and the amount that is required in the diet.

Many Americans are not aware of what the actual serving size for protein sources are. It is easily understood that they would be confused because the smallest size steak that can typically be ordered in a restaurant is around 8 ounces. According to the USDA food guide pyramid, the average adult needs approximately 5 to 7 ounces a day. Obviously if a person has already consumed protein at breakfast like eggs, protein at lunch like a chicken sandwich, and then goes out for dinner at a steak house, the person will intake way to much protein!

Other protein sources like nuts, nut butters, seeds, dairy, and beans must also be considered. It is good to consume a variety of protein sources while meeting the recommended RDA's. A 3 ounce portion size of meat is about the size of a deck of cards. A serving of peanut butter, which is 2 tablespoons, equivalents to a 2 ounce serving of protein is about the size of a ping pong ball. One egg would equivalent to one ounce of protein. A half a cup of beans would equal a 2 ounce serving. Two tablespoons of hummus equals 1 serving. A fourth of a cup of nuts would equal a 1 ounce serving. It is important to consume other types of protein such as nuts, bean, and seeds because of added fiber, healthy fats such as monounsatured fat and they have less overall saturated fat than meat.

A great source to learn more about correct portions sizes of protein rich foods (mainly pertaining to the "meat and beans group") is http://www.mypyramid.gov/.


Resources:
1) (2009, April). What counts as an ounce?. Retrieved August 5, 2009, from MyPyramid.gov Web site: http://www.mypyramid.gov/pyramid/meat_counts.html
2)Baranowski T, Berenson G, Cullen K, Nicklas T, (2001).Eating Patterns, Dietary Quality and Obesity. Journal of the American College of Nutrition, 20(6), 599-608.
3) Fulgoni, V (2008).Current protein intake in America: analysis of the National Health. The American Journal of Clinical Nutrition, 87, 1554-1557.

Protein and Athletes

Athletes need protein primarily to repair and rebuild muscle that is broken down during exercise and to help optimize carbohydrate storage in the form of glycogen. Protein is not an ideal source of fuel for exercise, but can be used when the diet lacks adequate carbohydrate. This is detrimental, though, because if used for fuel, there is not enough available to repair and rebuild body tissues, including muscle (1).
A sedentary person, a marathon participant, and a body builder of the same weight have different protein needs. Protein requirements depend upon body weight, body composition, rate of growth, physical activity level, type of physical activity, adequacy of energy and carbohydrate intake, and illness or injury. The protein needs for athletes are greater than the recommended 0.8 grams per kilogram of body weight recommended for sedentary people. Strength training athletes need about 1.4 to 1.8 grams per kilogram (2.2lbs) of body weight per day. Endurance athletes need about 1.2 to 1.4 grams per kilogram (2.2lbs) of body weight per day (2).
Endurance exercise alters protein metabolism and increases amino acid oxidation leading to increased protein needs. The increase in need is dependent upon the intensity and duration of the exercise, with higher intensity and longer bouts of exercise associated with increased protein needs. Individuals such as body builders, who are using resistance training to increase muscle mass, require a protein intake greater than for sedentary people and endurance athletes (2). Body builders' training programs typically include a maintenance phase, a muscle-mass building phase, and a tapering or cutting phase. Protein needs during these times vary. During the maintenance phase, recommended protein intake is 1.2 grams per kilogram body weight for maintenance of muscle mass. During the muscle-building phase, a protein intake of 1.4-1.8 grams per kilogram body weight is recommended. During the tapering or cutting phase, body builders significantly decrease their calorie intake. During this special phase of calorie and carbohydrate restriction, protein needs increase to 1.8-2.0 grams of protein per kilogram body weight to compensate for the use of protein for energy during this hypocaloric phase (3).
Adolescent athletes involved in high-intensity physical activity must meet the nutrition needs of growth combined with physical activity. Their protein needs vary from 1.8-2.0 grams per kilogram body weight. The timing of protein intake is also important. Protein that is consumed with carbohydrate within an hour after exercise stimulates the release of insulin and growth hormones, and therefore, growth of muscle mass. An inadequate amount of carbohydrate in the diet can result in reduced muscle glycogen stores in the muscle and liver, decreased endurance, decreased maximal effort, decreased serum glucose levels, and increased risk of hypoglycemia (4).
Protein intake should not exceed 2.0 grams per kilogram body weight. Excess protein intake is associated with dehydration, increased risk of certain cancers, increased calcium excretion and increased risk of osteoporosis, and reduced intake of vitamins, minerals, fiber and phytochemicals (4).

References
1. The Protein Power Diet. http://www.webmd.com/diet/protein-power-what-it-is. Accessed on August 1, 2009.
2. Mahan LK, Escott-Stump S. Krause's Food & Nutrition Therapy, 12th Ed., St. Louis, MO: Saunders Elsevier Pub.; 2008.
3. Rodriguez NR, Di Marco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 2009; 41 (3): 709-31.
4. Zeratsky K. High protein diets: Are they safe? http://www.mayoclinic.com/health/high-protein-diets/AN00847. Accessed on August 2, 2009.

Protein Shakes

More and more people are looking for information on protein shakes either to lose weight or to enhance their physical performance. They have been on the market for a while now and in stores like GNC or other health food stores. There are benefits to drinking protein shakes even if you are not someone who works out hours a day everyday. Protein shakes are good for healthy people that are pretty active in their lifestyle, running, yoga, etc. According to a WebMD article on protein shakes they are "Safe for people who are healthy and fit, protein shakes are used mainly by athletes who need nourishment right after their workouts, says Jose Antonio, chief executive officer and co-founder of the International Society of Sports Nutrition (ISSN). 'Most people can't make a meal immediately post-workout', he says. 'So these ready-to-drink shakes are really your best alternative'." [1]
There are people out there who think that protein shakes will make you lose weight. There are calories in protein therefore comsuming too much protein can make weight loss hard. There are some companies that claim protein shakes alone can help you lose weight but there is no evidence according to Katherine Zeratsky, R.D., L.D, writer for Mayo Clinic.com. [2]
There are benefits for taking these protein shakes, they help the body recover from an intense workout by restoring the glycogen in your body which is often used up during workouts.
According to WebMD even people who only work out 3 or 4 times a week can benefit from these. Having the protein shake after a run can help repair the muscle from the damage that is done during a workout.
What is in a Protein Shake?
Protein shakes can vary in the contents. They can range from 100% protein to having carbohydrates and fats added in. Protein shakes can also contain: Casein, Milk, Whey, Egg and Soy. Depending on how much you work out and what you are aiming for with your body determines what type of protein shake is good for your body. According to Jose Antonio, chief executive officer and co-founder of the International Society of Sports Nutrition (ISSN), "If your goal is to lose body fat, change to a protein shake that's mainly protein, has fewer carbohydrates, and only a little bit of fat, such as Slim-Fast. 'Make sure the product is more than 50% protein if your goal is body fat loss', Antonio says. " [3]
For the middle range people out there, between endurance folks and body builders, a popular protein shake is Muscle Milk, which contains milk proteins as well as carbohydrates and fats.
People often ask why do they need to drink protein shakes right after they work out if they are getting "enough" protein during the day. Protein in the building block for our body, for some people its hard to get all the protein you need in one day, that's why these shakes are also helpful!



1 and 3. Kathleen M. Zelman MPH, RD, LD January 25, 2008
Protein Shakes , WEBMD August 2, 2009
www.webmd.com/a-zguides/proteinshakes
2. Katherine Zeratsky, R.D., L.D. April 19, 2008
Expert Answers Mayo Clinic August 2, 2009
http://www.mayoclinic.com/health/protein-shakes/AN01332

Vegetarian Sources of Protein

Image provided by MyPyramid.gov (http://www.mypyramid.gov/tips_resources/vegetarian_diets.html)

A lot of people might be surprised how much protein can be consumed in a plant-based diet but it is still a matter of concern when it comes to a vegetarianism.

The primary focus of concern is getting adequate protein and all 8 essential amino acids. Most plant proteins do not contain all 8 essential amino acids. Those that do may be considered controversial and avoided; soy, for example contains all 8 essential amino acids. To get all 8 essential amino acids, a vegetarian can easily combine food products that compliment eachother. For example, beans are low in the amino acid lysine but rice is rich in lysine. The great thing about such a combination is that it may exist naturally in many recipes and cultures. For example, rice and beans are found frequently in Mexican meals. Also, the two items do not have to be eaten together. It should be sufficient to eat the two items within hours of each other or within the same day. This is also a subject debated by many professionals.

Chart provided by:http://www.savvyvegetarian.com/articles/get-enough-protein-veg-diet.php

Plant proteins are also considered low quality proteins because they are measured against the protein in eggs, the ideal protein. However, some vegetarians consume eggs, such as lacto-ovo or ovo-vegetarians, and more of a problem for stricter vegetarian diets such as the vegan diet.

Great sources of vegetarian protein include nuts, seeds, legumes, eggs, and some dairy products. However, some protein products may be high in fat and cholesterol so those should be used less often or in balance with other meals that are lower in fat and cholesterol. Here is a chart that shows various forms of protein and their calories. It's important to keep in mind that while plant-based proteins do appear smaller- a vegetarian could certainly consume more servings throughout the day to get the amount they need.

Although there will always be controversy over vegetarian diets, the ADA, among many organizations, including the Mayo Clinic and the American Diabetes Association, encourage the benefits of a vegetarian diet through online publications and position papers. In fact, the new position paper by the American Dietetic Association explains a lot of information regarding vegetarian diets including information on protein. It can be found here: http://www.vrg.org/nutrition/2009_ADA_position_paper.pdf

There are also a lot of athletes who are vegetarian, even vegan, who manage to get adequate protein intake. Some examples include (from the website www.veganathlete.com/vegan_vegetarian_athletes) :

• 
  
  Brenden Brazier- Ironman triathlete


• 
  
  Scott Jurek- Ultramarathoner


• 
  
  Bill Pear- 4 time Mr. Universe Winner


• 
  
  Art Still - Buffalo Bills/Kansas City Chiefs MVP, Hall of Fame

And many, many others!

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Resources:

International Vegetarian Union: http://www.ivu.org/faq/protein.html

Vegetarian.About.Com: http://vegetarian.about.com/od/healthnutrition/tp/protein.html

The American Dietetic Association: http://www.eatright.org/cps/rde/xchg/ada/hs.xsl/nutrition_5105_ENU_HTML.htm

The Vegetarian Nutrition Dietetic Practice Group: http://www.vrg.org/

My Pyramid Dot Gov: http://www.mypyramid.gov/tips_resources/vegetarian_diets.html

Protein, how much is too much?

TOO MUCH PROTEIN AND THE ACID ASH IT LEAVES AS RESIDUE

Consumers today are bombarded with health and dietary information that is both correct and incorrect, as well as ridiculous. The idea that an abundance of protein is required from several sources including meat, dairy and supplements is primarily generated by the American Dairy Association, United States beef industry, and the pharmaceutical and supplement providers rather than the Food and Drug Administration or the United States Department of Agriculture. During this review I will explain the protein amounts that are required, the findings of various studies and some of the harmful effects of excess ingestion of protein, both short term and long term.
Consumption of protein has an acidifying on the body. Barzel1 in her article “Excess dietary protein can adversely affect bone” explains that once the protein is digested, it leaves an acid ash which the body has to make more basic or alkaline so it can be excreted. Before we get into that, let’s discuss what the protein requirements are. Mahan and Escott-Stump in their book Krause's Food & Nutrition Therapy2(p 465) explain that the United States Recommended Daily Allowance (RDA) for adults is eight tenths of a gram of protein per day for each kilogram of body mass. So that means the RDA of protein for a one hundred eighty pound man is about sixty-five grams of protein for the day. One hundred eighty pounds converted to kilograms is approximately eighty-two kilograms, multiplied by point eight grams gives about sixty-five grams. If this man consumes a breakfast of three eggs, half pound of ham and a glass of milk that far exceeds (approximately seventy-five grams of protein) the daily intake allowance. If the individual has the audacity to actually have lunch and dinner, maybe a couple of quarter pound cheeseburgers and a nice twelve ounce steak with the fixings, they could easily quadruple (or more) the RDA for protein. Enough about the American intake, Mahan and Escott-Stump also include in their book the Dietary Reference Intakes (DRI) which are different for certain groups of people. For example in pregnant women(p 172) “There is an additional protein requirement for a pregnant women to support the synthesis . . . and fetal tissues.” Not enough protein during pregnancy can have bad effects and is usually accompanied with lack of energy intake, as well. Lactating women(p 287) require an additional twenty-five grams of protein which is more than fifty percent increase from a non-pregnant, non-lactating woman’s requirement of forty-six grams per day. Infants and children(p 227) require approximately 1.1 grams and .95 grams per kilogram of body mass, respectively.
Whatever the protein requirements are for any group of individuals, the fact remains that certain foods leave an acid ash1 when metabolized. These foods are cheeses, grains, fish, meat and meat products. While not as severe as those listed above, milk and non-cheese dairy products leave an acid ash as well. When this happens the body must take corrective actions to buffer this acidity. The best way to do this is other than consuming less protein and grains is to consume alkaline ash producing substances. What are alkaline ash producing foods? Table 11 gives the average potential renal acid loads (PRAL) of various substances. The items that have the lowest (negative) PRAL are fruits and vegetables along with red wine, white wine and some mineral waters. Back to the standard American dietary intake, not only is the average diet high in protein; it is low in vegetable and fruit intake. The body will do what it has to do to correct the acidity and survive. The kidneys will not allow urine with a potential for hydrogen (PH) below five to be excreted. They give an example of a 330 mL soda with a PH of about three would require one hundred times that amount of water (approximately 33 liters) to buffer the acid PH of the 1/3 liter of soda. Since this does not happen, the body buffers it chemically. It can use any alkaline substance in the body to buffer the acid. The ones most abundant in the body are calcium, phosphorus, magnesium and sodium. Urinary calcium increases when there is acid that needs to be buffered for expulsion. The test mentioned compares two groups the first with point eight grams of protein per day and the second with 2 grams of protein per day. “Urinary calcium nearly doubled with the higher protein diet.” The calcium has to come from somewhere and the bones are the biggest deposit of calcium around. Lutz and Linkswiler3 found similar results in their research on post-menopausal women. Their study observed eight subjects with dietary protein of fifty milligrams per day, then increased to one hundred and ten milligrams of protein per day. The subjects were supplemented to increase their calcium, magnesium and phosphorus intake up to 713, 323, and 1078 milligrams per day. They found that even when the subjects were receiving over seven hundred milligrams calcium per day, it was still not enough to balance their calcium intake to urinary calcium.
Allen4 in the article “Calcium bioavailability and absorption: a review” contends that the RDA of calcium may not be adequate and definitely does not apply to all groups. Also, that just because the calcium is available for absorption does not mean it will be absorbed. This is dependent on several different factors “such as calcium and vitamin D status, age, pregnancy, lactation, and disease, which affect the absorption of calcium once it is available in the intestinal lumen.” Certain amounts of calcium intake are lost in feces, sweat and sweat. These amounts do not deviate much when the amounts of dietary calcium change. Allen goes on to explain that dietary protein does not affect the bioavailability of calcium nor affect the absorption rate of the calcium. Increase in urinary calcium correlates to the increase of dietary protein, when the protein intake goes up the urinary calcium goes up. “The negative balance is not prevented by a high calcium intake.” The increase in dietary calcium is not adequate to rectify the acid residue from increase protein metabolism.
Kerstetter, O’Brien, and Insogna5 in their article “Dietary protein, calcium metabolism, and skeletal homeostasis revisited,” reviewed over twenty clinical research projects and found on average “for every 50 g increase in dietary protein, there is . . . 1.6 mmol increase in 24-h urinary calcium excretion.” They further state that with medium protein intake (100-150% of RDA) that calcium and skeletal metabolism stabilizes. They also contend that low protein intake leads to poor calcium absorption into the body, yet did not expound on the long term impact on bone health. They conclude that only thirty to fifty percent of Americans had “moderate” intake of protein. They were uncertain whether high protein intake caused increased absorption of dietary calcium. As well as whether the increase in bone resorption and the hypercalciuria were linked and what the long term results were in regards to fracture rate.
When Margen, C’hu, (et al) 6 published their “Studies in calcium metabolism. 1. The calciuretic effect of dietary protein” they directly and positively correlated the increase in urinary excretion of calcium with the increase in protein consumption. The study threw out the first three days of their controlled observations to rule out the affect of previous intake on their results. After that, any increase of protein directly resulted in increase in calciuria. The subject’s higher calcium level maintained itself at the new higher level and did not try to return to the previous average level. The increase in urine calcium was not proportional between subjects on the same diet. Some subjects had a large increase of calciuria with small increases in protein and others required a large increase of protein to increase the urine calcium. They found that “All of them, however, excreted more calcium in the urine whenever the protein intake increased.” On average the increase was over eight times when the subjects had an increase of ninety-six grams per day of nitrogen from protein. They determined that the overall effect of dietary protein on the urinary calcium can be shown as a percentage of urinary calcium during their study. This removes the effect of varying calcium intake from the calculations and directly relates it to the protein intake. This result was only for calcium, not the other minerals they observed such as magnesium, sodium, potassium, and phosphorus. They found no “consistent or significant” correlation to the urinary levels of these other minerals to the protein intake or the increase in urinary calcium.
The overall consensus from the research is that the amount of protein in the American diet can be detrimental. All but one project rule out the increase in dietary calcium as causing the increase in urinary calcium. Not only does the bone resorption required to buffer the acidifying effect of the metabolized protein cause immediate concern, the long term affect of the pulling calcium from the bones may be directly related to the problem of osteoporosis. In addition to that, this excessive buffering of the acid from too much protein causes the kidneys to be overloaded and overworked. This could potentially lead to renal failure. If Americans in general knew the amount of protein required and actually took action to modify their intake protein (and other acid ash producing foods) accordingly, along with increasing their consumption of fruits and vegetables, they could prevent this negative calcium affect of protein.
Reference Section
1. Barzel US, Massey LK. Excess dietary protein can adversely affect bone. J. Ntr. 1998;128:1051–1053.
2. Mahan LK, Escott-Stump S. Krause's Food & Nutrition Therapy, 12th Ed., St. Louis, MO: Saunders Elsevier Pub.; 2008.
3. Lutz J, Linkswiler HM. Calcium metabolism in postmenopausal and osteoporotic women consuming two levels of dietary protein, Am J. Clin. Nutr. 1981;34: 2178-2186.
4. Allen L. Calcium bioavailability and absorption: a review, Am J. Clin. Nutr. 1982;35: 783-808.
5. Kerstetter JE, O’Brien KO, Insogna KL. Dietary protein, calcium metabolism, and skeletal homeostasis revisited, Am J Clin Nutr 2003;78(suppl):584S–592S.
6. Margen S, C’hu JY, Kaufmannz, NA, Calloway DH. Studies in calcium metabolism. 1. The calciuretic effect of dietary protein. Am J Clin Nutr, 1974;27:584-589.

Introduction and Thank You!

Hello everyone!

Per Nutrition Education, our group has created a blog for your enjoyment.

This blog will currently be geared towards Protien.

Each contributor will contribute to a different (possibly overlapping) aspect of protein.

I would like to introduce the contributors and the aspects of protein they will be discussing:

• Colleen McCarthy: Protein shakes
• Michael Childs: Types of protein
• Julie Conant: Vegetarian sources of protein
• Lisa Ferrone: Protein and athletes
• Daren McKean: Acid ash residue from protein
• Ashley Patterson: Too much protein

Please subscribe to the blog so that when we contribute to the blog, you'll know about it!

Thanks!