1.            Description

Met-Rx can be used as a meal supplement or meal companion. It is mostly used by body builders in order to build body mass. It is packaged in the form of food bars or powdered shakes. (www.metrx.com/tutorials-and-quiz/quiz.html) The purpose of this treatment is to "support protein synthesis, energy production, and fat utilization" (www.met-rx.com/faq/default.htm). The ingredients contained in these combinations allow the body to acquire all the necessary nutrients for maximum metabolic effect.

2.          Types of Protein Supplements

Shakes are used so that the time consuming calorie counting, etc. can be avoided. They are also designed to "maximize the oxidation and storage potential of some metabolic pathways (protein and carbohydrates) and limits others (fat)" (www.metrx.com/tutorial-and-quiz/lesson7c.html). Currently, whey protein has the highest Biological Value (a number used for comparing protein value in foods.) The fact that whey protein was produced as a result of milk protein and there is no inclusion of fat or lactose allows whey protein to be very beneficial. Whey protein has also shown an increase in levels of glutathione (an antioxidant which is necessary in a healthy immune system). (www.powersupplements.com/protein.htm) For this reason, the University of Nebraska Medical Center studied the effects of a protein diet on hamsters. They concluded that the "life span of hamsters was extended by 60% by supplementing their diet with whey protein" (www.powersupplements.com/protein.htm). Considering this study deals with hamsters, the results can not be assumed exact for humans, nonetheless they are encouraging.  

3. Food Vs. Protein Supplement

Nutritional supplements have become so popular in recent years that they are easily purchased at health stores, gyms, and even over the Internet. These products are sold without FDA approval of safety or effectiveness. In a study done by the Department of Exercise Science at the University of Massachusetts, Amherst, an increase in body mass due to protein supplements was "most likely water retention in muscle but could also be due to some new muscle protein"(Clarkson 1999). Though athletes need more protein to keep a nitrogen balance, it is easily obtained in a normal diet. The Department of Pharmacy at Shands Hospital concludes that "protein supplementation can lead to dehydration, gout, liver and kidney damage, calcium loss, and gastrointestinal effects"(Beltz 1993).  

4.          Protein Supplement and Athletes/Bodybuilders

Scientists have proven that the break down of protein in amino acids are needed in the build up of muscle. As a result, Met-Rx contains whey protein, metamyosyn, as well as other proteins. Athletes and Bodybuilders are looking for a way to increase muscle mass, increase endurance, or reduce body fat without damaging their bodies like using steroids, etc. Protein supplements give them the added amino acids for muscle build up, however; "the normal dietary intake of protein is adequate for athletes as long as the energy intake is sufficient to maintain body weight" (Dohm 1984). In a study by the Human Performance Laboratory at the University of Houston, a clinical trial showed that "growth hormones were significantly elevated during resting conditions 60 minutes after amino acid ingestion compared with the placebo trial" (Arslanian 1997). This conclusion, however; can not be assumed correct with all supplements due to lack of regulations.

    5.          Protein Supplement and loss of LBM in Patients

Dr. Scott Connelly developed the Met-Rx nutritional program as a result of observations/ experiments dealing with critically ill patients. Connelly attempted to resolve a problem doctors have with patients who must be treated for their primary condition plus the loss of lean tissue. The loss of lean tissue is due to the body using body protein as energy for metabolism instead of fat reserves. Connelly refocused his studies to include healthy subjects and their exercise habits in order to create Met-Rx. (www.metrx.com/tutorials-and-quiz/quiz.html) It is assumed that if the body consumes certain nutrients on a regular basis, then certain illnesses can be avoided. With technological advancements, it is now possible to isolate these nutrients and package them into small capsules. Met-Rx has incorporated a mixture of protein, carbohydrates, fat, and calories at the approximated percentages that the body needs. (www.met-rx.com/faq/default.htm) As reported in Nutrition, patients who recently underwent gastrointestinal surgery were given an increased intake of protein and energy over a four month period. After this period, the results concluded a significant gain in lean body mass. This is an important discovery due to sedentary patients and chronically ill weight-losing patients who need stimulation for protein synthesis in the battle to gain LBM.

6.          Claims

The high levels of proteins used in nutritional supplements have often caused people to be wary. An experiment dealing with rats and protein intake concluded "rodents on high-protein diets developed a rather serious kidney condition known as nephrocalcinosis" (www.met-rx.com/faq/default.htm). However, this situation has not been documented in human beings. Furthermore, "epidemiologic and clinical observations prove quite conclusively that even extraordinarily high levels of protein do not result in kidney or liver dysfunction" (www.met-rx.com/faq/default/htm). However, these observations were not studied over a long period of time. The protein not used by the body will be exited as waste, putting a lot of stress on the liver and kidneys if subjected over a long period of time. (www.powersupplements.com/protein.htm)

  7.          Supporting Evidence

In a clinical trial by the University of Wisconsin on newly diagnosed cancer patients, nutritional supplements and food intake were compared. This study concluded "nutritional supplements can be used to increase total caloric and protein intake without causing a significant reduction in food intake." (McCarthy 1999) This reveals that patients needing more nutrients are able to receive them through this method as well as eating correctly.

    8.          Recommendations

The use of protein supplements should be cautious due to unproven claims, uncertain quality, and safety of long-term use. Due to the Dietary Supplement Health and Education Act of 1994, which allows marketers to make certain statements of nutrition support to be made on supplement labels, contents of these supplements have had no authoritative review (Nesheim 1999).

    9.          References

(1) Beltz, SD and PL Doering. (1993). Efficacy of nutritional supplements used by athletes. Clinical Pharmacy. Dec;12(12);900-908.

(3) Dohm GL. (1984). Protein nutrition for athletes. Clinical Sports Medicine. Jul;3(3):s595-604.

(4) Jenson, MB and I Hessov. (1997). Dietary supplementation at home improves the regain of lean body mass after surgery. Nutrition. May;13(5):422-430.

(5) McCarthy, D and D Weihofen. (1999). The effect of nutritional supplements on food intake in patients undergoing radiotherapy. Oncol Nurs Forum. Jun;26(5):897-900.

(6) Nesheim, MC. (1999). What is the research base for the use of dietary supplements? Public Health Nutrition. Mer;2(1):35-38.

(7) Arslanian, S. and S DaSilva, FL Goss, J Kang, KF Metz, RJ Robertson, RR Suminski, and AC Utter. (1997). Acute effect of amino acid ingestion and resistance exercise on plasma growth hormone concentration in young men. Int. J. Sport Nutrition. Mar;7(1):48-60.