I have asked Dez to share a research article that she wrote for an assignment in her statistics class at the University of California, Los Angeles. If you are interested in hearing more from Dez, please visit her own personal blog.All different kinds of products constantly inundate our everyday lives. From grocery and department stores to internet and television, and everything in between, we are surrounded by products that advertise their uses and effectiveness to us as consumers. Some products claim their effectiveness to be “clinically proven” or “tested,” which may increase the likelihood of such a product being bought and used by many people all over the world. For example, a popular product called Pro Clinical Hydroxycut claims to “provide faster weight-loss results than diet or exercise alone” as per the results of clinical tests (Iovate, 2010). However, how many people actually research the claims that products make before they purchase them? How does one know that the claims are valid or true?
To answer these questions about products marketed to the public, an assessment was done on the claims made by Pro Clinical Hydroxycut. The effectiveness of Pro Clinical Hydroxycut is said to be due to its ingredients, which are listed on the website (Iovate, 2010). There they detail two studies that were done to test the effectiveness of Pro Clinical Hydroxycut. The first study was done by a “third-party,” someone unrelated to or affiliated with Hydroxycut (Iovate, 2010). According to Paul C Cozby, author of Methods in Behavioral Research, research done by a third-party tends to have low bias effect (2009). For example, had the study been done by the makers of Hydroxycut then one would wonder if the results of the study were at all biased due to the company’s interest in an outcome that supports their product. In addition, this study used a “randomized, double blind, placebo” procedure, in which the experimenters and participants did not know which substance they are being given, Pro Clinical Hydroxycut or a placebo (Iovate, 2010). According to Cozby (2009), a randomized, double blind, placebo procedure is valuable to experiments as it protects against expectancy effects that the experimenter or participant may have. This is due to the fact that being given a drug or pill is sometimes enough to produce an effect, even if the treatment is not a drug at all but some other substance, as the participant and/or the experimenter expects a change once the substance has been administered (Cozby, 2009). These precautions greatly strengthen the results of the study as we can be sure that the effects are not due to a bias.
While this first study seems to have minimized possible bias effects, one has to wonder where the researchers pulled their sample from. Nothing is said about who participated in this study or how they came to be participants. Cozby (2009) suggest that in choosing a sample for a study it is important to find people who represent the population at large. In order to decide whether their sample is a good representation one needs to know more about the participants of this study and how they were selected. For example, did the participants vary in height, weight, ethnicity, and gender? These are important factors to consider in regards to the effectiveness of Pro Clinical Hydroxycut as everyone loses weight at different rates, has more or less weight to loose, or may have other qualities, characteristics, or circumstances that makes one more or less likely to lose weight than others. Also, was the sample selected randomly or did the participants volunteer or were they chosen because they possessed some quality of interest to researchers? We can only be sure that this sample is a fair representation if every person in the population had an equal chance of participating in this study (Cozby, 2009). Each of these factors, and others that researchers may not be aware of, can act as a confounding variables that may alter or bias the results of the study in some way (Cozby, 2009).
Another point to consider in this study is how the participants were tested. Pro Clinical Hydroxycut claims that their product gives “faster weight-loss results than diet and exercise alone,” which leads one to assume that this study was operationally defined as weight-loss/time (Iovate, 2010). This claim also leads one to believe that they tested their effects against a group of individuals who were not given any treatment other than diet and exercise. However, the study explains that over a 12 week period researchers used an experimental group, who received Pro Clinical Hydroxycut, and a control group, who received the placebo. In other words, each group was given some form of treatment for 12 weeks, which is not what the claim leads us to believe. This claim would be much better supported had they also measured the effects of weight-loss with a true control group who did not receive Pro Clinical Hydroxycut nor a placebo and only did diet and exercise alone for the same 12 weeks, as stated in the claim. Those results could then be compared to the experimental and placebo groups which would then provide a more descriptive measure of the effectiveness of Pro Clinical Hydroxycut. Furthermore, the study states that both the experimental and placebo groups were given a “calorie-reduced diet,” but no mention of any exercise treatment (Iovate, 2010). This makes the claim look rather false as the claim explicitly states it is better than “exercise alone” (Iovate, 2010). Also, if exercise was not held constant among all participants then it would act as another compounding variable that would most definitely affect the results of the study (Cozby, 2009).
The results of this study demonstrate that in 12 weeks the participants in the experimental group who used Pro Clinical Hydroxycut lost significantly more weight than that of the placebo group (Iovate, 2010). They do not state the type of test the researchers used to gather these results. However, one can assume that they used a pretest-posttest design where each participant was measured for weight, randomly placed in the experimental or control group, given the appropriate treatment, and then measured for weight again at the end of 12 weeks (Cozby, 2009). Here the independent variable is either Pro Clinical Hydroxycut or the placebo, depending upon the group type, while the dependent variable is weight lost over a 12 week period. A second, follow-up study was completed by the makers of Hydroxycut showing similar results as the first study (Iovate, 2010). This study was only an eight week study, as opposed to the 12 weeks in the first study (Iovate, 2010). It appears that this study was similar in design to the first as they too used an experimental and placebo group, but there is very little describing this second study and more information is needed in order to make a concrete comparison. However, the results of both of these studies are very similar, which seems to confirm the reliability of Pro Clinical Hydroxycut (Cozby, 2009). Conversely, had the first study reported very different results than the second study one would not be able to rely on the effectiveness of Pro Clinical Hydroxycut. Moreover, disparate results would make one question the methods of the experiment and the motives of the experimenters.
Lastly, one must assess the validity of both of these studies as this determines whether or not the study actually measured what it was supposed to measure, in this case, weight-loss produced by Pro Clinical Hydroxycut (Cozby, 2009). Both of these studies appear to be high in construct validity, face validity, and internal validity (Cozby, 2010). However, these studies may be lacking in external validity as researchers did not adequately describe the sample they used as described above (Cozby, 2009).
In conclusion, it appears that Pro Clinical Hydroxycut does indeed aid in weight loss. However, the extent of weight lost is questionable and possibly different from what is stated in the claim. The biggest concern being the claim states that Pro Clinical Hydroxycut is better than “diet and exercise alone,” which may be true, but was not actually tested in research (Iovate, 2010). Therefore, consumers who purchase this product may be making a choice based upon a claim that does not have a strong research base and may see dramatically different results that what the claim asserts.
Pura Vida!
Alica Ryan, NTP
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