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Metabolife:
Diet Pill or Death Wish?
The Product
A.)
What is the
purpose ofMetabolife?
Metabolife is a company that produces dietary supplements
designed to trigger weight 
loss
and produce higher energy levels for its users. However these supplements goes
far beyond a simple diet pill according to the Metabolife mission statement
which states, “we[Metabolife] thrive on creating products that are safe and
effective. Most of all, we have pride and dedication to creating products that
improve the health and wellness of our customers.” (http://www.metabolife.com/about/) Thus,
through weight-loss and increased energy levels triggered by the supplements,
Metabolife International strives to create a better quality of life for its
users. Although the Metabolife company has seven different products on the
market, Metabolife 356 is the most well known and therefore the focus of this
paper.
B.) How does
Metabolife 356 achieve its purpose? How does it work and what are the
mechanisms?
Metabolife 356 causes weight-loss by raising user’s metabolism which causes a thermogenic response which refers to a generation of heat due to physiological processes. This response in turn metabolizes fat in the body, leaving the lean muscle in tact. Furthermore, due to the unique herbs and nutrients that make up these supplements, Metabolife 356 produces energy levels higher than those typically seen in reduced calorie diets. Finally, these dietary supplements curve and suppress appetite before meals. However, for maximum results it is important that user’s of Metabolife 356 maintain a healthy lifestyle which includes monitored diet, exercise, and hydration.
Diana Before Diana
After
“…I lost 75 pounds and have kept if off for almost 2 years.”
C.)
What claims are
made about the effectiveness of this treatment?
To demonstrate the effectiveness of Metabolife 356, Metabolife International provides testimonials on its website which illustrate the success of its users. According to one user, Diana, “The Metabolife 356® curbed my appetite, and made it extremely easy to lose weight. I have never been able to lose weight, but with Metabolife, I lost 75 pounds and have kept it off for almost 2 years. I cannot tell you how grateful I am to Metabolife. People that I went to high school with do not even recognize me. Losing weight has been one of the best experiences of my life. My self-esteem is great now, and my confidence level is through the roof. I feel like I can do just about anything now. Before I was very quiet, and reserved; now I am very outgoing, and can talk to just about anyone. My life is wonderful now!” (http://www.metabolife.com/successstories/lifelongchallengeDetail.jsp?id=428)
While this is only one of many
success stories, an obvious theme emerges about the effectiveness of the
supplement. Not only do users shed pounds easily, but their weight-loss
generates a better quality of life.
D.) What evidence is offered to support this claim?
In order to support the
weight-loss claims made in testimonials, the Metabolife website provides
several ‘facts’ concerning the safety and effectiveness of Metabolife 356.
These bits of information report that obesity is a leading cause of death in
the
E.) Who is presenting this information, and why are they
presenting it?
All of the information covered
is presented by Metabolife International on their web site (www.metabolife.com). This website is
designed to inform inquiring minds about their products and in turn, to produce
sales. Thus, the motivation behind this presentation of information is to
generate a profit for the company while creating customers satisfied with their
weight-loss results.
The Research
A.) Does Metabolife 356 really work?
According to Metabolife
International, Metabolife 356 contains a number of ingredients that create a
‘unique’ blend of herbs and nutrients that trigger weight loss. However, it is
the ingredient ephedra, an ancient Chinese herb, and ephedrine, the synthetic alkaloid
form of ephedra, which are responsible for these results. Many studies have
been conducted on the efficacy of ephedra-containing dietary supplements on
weight loss and all have produced similar results; these supplements do in fact
cause weight loss. These results are greatly represented by a research review
paper funded by the Agency for Healthcare Research and Quality (AHRQ) that took
case reports submitted to the U.S. Food and Drug Administration (FDA) as well
as dietary supplement manufactures and performed a meta-analysis on the
reports. From this analysis the AHRQ concluded that the temporary use of
ephedra/ephedrine-containing dietary supplements is associated with
considerable short-term weight loss. More specifically, the report suggested that
users of ephedra/ephedrine-containing supplements lost around 1.3 more pounds
per month for up to six months in comparison to users who received placebo
controls. These results signified an eleven percent weight loss in users as
compared to their pre-supplemental weight. Yet the reports went beyond testing
for single ingredients in dietary supplements and looked at the overall effect
of the combination of ephedrine and caffeine versus the placebo control. The
results of these reports suggested that when combined with caffeine,
ephedrine-containing supplements yielded 2.2 pounds lost per month more than
the placebo; a total loss of eleven percent. Finally, the study compared the
effects of ephedrine versus ephedrine plus caffeine supplements and found that
the addition of caffeine produced a weight loss of 0.8 more per month than
ephedrine alone. The study also analyzed the effectiveness of ephedra versus
the placebo and ephedra plus caffeine containing herbs and found results
similar to those of the ephedrine tests. From the study conducted by the AHRQ,
it was concluded that ephedra/ephedra-containing supplements did in fact cause
weight-loss and that these effects were heightened by the addition of the caffeine
or caffeine-containing herbs (Shekelle, Morton, Maglione, 2003). Thus, because
Metabolife 356 contains ephedra (Ma Haung) and caffeine-containing herbs
(Guarana) its weight-loss claims have elements of truth. 
These
claims however, do not compare to those made in testimonials on the Metabolife
website which reported users losing 75 and even one hundred pounds. Therefore,
while the product does in fact cause weight loss, it is no where near the
extent that Metabolife claims.
In
light of these findings, the AHRQ study pointed out two factors that disheveled
the effectiveness of ephedra-containing supplements. First, the report found no
data concerning the long-term effectiveness of these dietary supplements and
therefore concluded that ephedra-containing supplements such as Metabolife 356
do not ensure continued weight-loss or maintenance after a six month period. To
support this finding is article by Shekelle et al. (2003) that says, “The
criterion not met is duration of treatment, as all trials but 3 reported less
than 6 months duration of treatment. 
Trails assessing 1
year of treatment are considered desirable, as are trials assessing what
happens to weight after the weight loss product is discontinued.” (Shekelle,
Morton, Maglione, & Suttorp, 2003, p. 1544) Thus, these articles show a
weakness in the Metabolife claims to weight loss. Second, the AHRQ study
conducted its meta-analysis under dose-response conditions which means that the
dosage was constant throughout the studies. Therefore, little can be said about
the effects of higher or lower doses on weight-loss. Since the AHRQ study was a
collaboration of many individual case reports over several years time, these
two parameters greatly reduce the certainty of Metabolife claims (Shekelle et
al., 2003).
B.) Is this dietary supplement as safe as Metabolife International claims
it is?
Just as there are many studies
that show that ephedra-containing dietary supplements are effective for
weight-loss, many of these studies also suggest that these supplements are not
safe. At the request of the FDA, a research review was conducted which analyzed
140 reports on ‘adverse events’ or harmful results associated with
ephedra-containing supplements in order to assess causation of the events. 
In this study, Haller and Benowitz (2000) found that 31%
of cases were definitely or probably related to the use of supplements
containing ephedra while 31% were possibly related. Of these 62%, they found
that 47% suffered from adverse cardiovascular events while 18% suffered from
adverse central nervous system events. These recorded events showed that hypertension
was the most common (17 cases), followed by heart palpitations or abnormally
rapid heart beats (13 cases), strokes (10 cases), and seizures (7 cases).
Furthermore, within the 62% of cases, ten of the adverse events resulted in
death while thirteen in permanent impairment. For example, one patient’s
adverse events that were definitely, probably, or possibly related to the
ephedra-containing supplement Metabolife 356 suffered from sever hypertension,
cardiac arrest, and hypokalemia (abnormally low amounts of potassium in the
blood), although having no preexisting conditions, died. Thus it is clear from
Haller and Benowitz’s (2000) research review that ephedra-containing
supplements and more specifically Metabolife 356 are directly associated with
adverse events and are therefore not safe.
The
research review paper published by AHRQ also noted the adverse events or
consequences associated with supplements containing ephedra. Although the
evidence of causation wasn’t conclusive, they found that
ephedra/ephedrine-containing supplements are linked with two to three times
more risk of nausea, vomiting, psychiatric problems such as mood changes and
anxiety, autonomic hyperactivity, and palpitations. In addition, the report
showed deaths (2), myocardial infractions or problems with the muscle tissue in
the heart (3), cerebrovascular accidents (9), seizures (3), and psychiatric
cases (5) as adverse events associated with ephedra ingestion (Shekelle, 2003).
The parallels between the data of the Haller and Benowitz (2000) report and
AHRQ report suggest that ephedra/ephedrine-containing supplements are
associated with serious health hazards. Therefore, the Metabolife International
mission statement that says, “…we strive on creating products that are safe and
effective” (http://www.metabolife.com/about/),
is only partially true. The question thus becomes, which is more important,
temporary weight-loss or long-term health and wellness?
References
http://www.metabolife.com/about/
http://www.metabolife.com/about/studiesDetail.jsp?id=121
http://www.metabolife.com/successstories/lifelongchallengeDetail.jsp?id=428
Haller,
CA & Benowitz, NL. (2000). Adverse Cardiovascular and Central Nervous
System Events Associated With Dietary Supplements Containing Ephedra Alkaloids.
The
Shekelle,
P., Morton, S., Maglione, M., Suttorp, M., Roth, E., Jungvig, L., Mojica, W.A.,
Gagne, J.,
Shekelle,
P., Morton, S., Maglione, M., Mojica, W.A., Suttorp, M.,
