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Beth Brunner

In addition to the negative social drawbacks associated with being obese, there are several physical and health risks. Because of this, the issue of obesity has become a widely discussed topic in the United States, especially during the past twenty years. Experts have estimated that somewhere between one in every four and one in every three Americans are obese, and over 55% of Americans over the age of twenty could be classified as being overweight. This number continues to rise.



       Body Mass Index (BMI) is a scale that uses height and weight to determine body fat. This figure can then be compared to averages to determine if one is at risk for particular health risks. A BMI over 25 is considered overweight, and over 30 is obese. The risk factors that are associated with obesity include diabetes, coronary artery disease, stroke, gallbladder disease, sleep apneas, and even some types of cancers. With all of these health concerns, why is obesity an increasing problem?

According to the Colorado Health Net the cost of treating obesity and health-related concerns amounts to about $68 billion per year, not including the $30 billion per year spent on additional weight loss diet programs and special foods.

There are many different viewpoints as to ways to attack the growing problem of obesity. Experts claim to have found an obesity gene, which explains that those who are obese have little control over it . When the gene is altered in mice, the amount of fat stored in the body varies. Because of the newness of the research and the obvious costs associated with this, it is not a likely procedure.

Even though genetic manipulation as a treatment for obesity is years away from practical application, science has attempted to tackle the problem of weight loss in several different ways. One such method uses insulin manipulative drugs in an effort to stabilize blood sugar that would otherwise aid in the storage of fat. Another method uses beta- receptor stimulation to increase thermogenesis. Additionally, appetite is controlled through the use of selective seretonin reuptake inhibitors (SSRI’s) and other appetite satiating drugs.

Special diets and exercise seem to be the most widely practiced method of weight loss, but with obesity being such an enormous health risk, many are seeking additional treatments. One researcher with the Mayo Clinic,, Maria L. Collazo- Clavell, M.D., claims that there is evidence that a loss of 5- 10% of body weight greatly reduces the risks of many of the conditions associated with obesity. She claims that the problem is that people have difficulty achieving and especially sustaining the weight loss.

Effort is indeed a large part of the battle, but in cases where a patients is too ill or too overweight to exercise, additional programs must be instilled. This is when other treatments must be used.

Drug company Roche has developed a new drug called Xenical (orlistat). Unlike many other diet drugs, Xenical is different from other drugs, like the ones discussed above, because instead of altering brain chemistry to suppress appetite or increasing the amount of energy expended, it works by inhibiting the action of an enzyme found directly in the gastrointestinal tract.




            Roche first submitted an application for Xenical to the FDA in 1996. It was recommended for approval in 1997, but then put on hold because of data that showed cases of breast cancer, which occurred during the clinical trials. It was later determined that these cases were due only to chance and in April of 1999, the FDA approved Xenical for use by doctors for obese patients, those with a BMI greater than 27.

According to the Xenical website,, the recommended dose of Xenical is one 120-mg capsule taken with liquid during a meal or within one hour of eating. It should be taken each time you eat a meal that contains fat. Although Xenical prevents the breakdown and absorption of fat, each meal should be well balanced and should not contain more than 30% of the calories from fat. If a meal is skipped or if it contains no fat Xenical should not be taken. It has been shown that doses above 120-mg, three times a day does not contribute to additional weight loss.

When the patients consumes a balanced meal and uses the drug as prescribed, some of the side effects experienced while taking Xenical may be reduced.

            So how does Xenical work?

            Calories that are not used by your body for energy are stored for later usage. The more you eat, the more you store, unless, you increase your energy expenditure by adding extra physical activities to your day.

            When food enters your stomach, a series of enzymes are used to break down each element of your meal. One particular type of enzyme is called lipases. Lipases are used to digest and break down fats. When Xenical is taken during a meal, it attaches itself to the lipases preventing them from breaking down the fats. If Xenical is attached to the lipase enzymes, they are unable to perform properly. The result is that all of the undigested fat cannot be absorbed into your body and thus it is eliminated through your bowels. Approximately one third of the fat that is consumed will be expelled in this manner.

            The process of undigested fat leaving the body is one major drawback to those taking Xenical. The side effects include oily rectal seepage, gas with discharge, oily bowel movements and frequent bowel movements. If more fat is consumed than is recommended, the symptoms worsen. This is another way in which Xenical works. If the symptoms worsen when extra fat is consumed, the person may become conditioned to watch out for the amount of fat that is consumed while taking the medication.


In addition to these side effects, the expulsion of fats from the body may reduce the absorption by the body of fat- soluble vitamins (A,D,E, and K) and beta- carotene. The FDA recommends that people who use Xenical should also take a supplement of these vitamins two hours before or after taking Xenical.

            According to, After one year of treatment, a diet aided by Xenical was more successful than diet alone in reducing weight. Weight loss was gradual in clinical trials, but the average user lost 13.4 pounds over the course of a year. Those only on a reduced calorie diet lost and average of 5.8 pounds. Twice as many Xenical users lost over 10% of their body weight than those who only dieted. In these cases, the average weight loss was 31 pounds, and ranged between 16 and 74 pounds.

            Additionally, it should be noted that the benefits of taking Xenical extend far beyond the physical changes. Dr. Collazo- Clavell announced that studies have demonstrated that Xenical also cause small, yet statistically significant decreases in cholesterol, insulin levels and blood pressure. This ensures that the benefits may be far reaching. Because of this, Xenical is also used for those who have high blood pressure, high cholesterol, or diabetes.

            Although the information handed down from Roche Company and the FDA seems to fully support this drug for use as a method of weight loss, many others have conducted their own research on Xenical to make sure.

            Hauptman, et al., conducted an experiment in a primary care setting to see how his results compared to those published. He conducted a two- year, single- blind, placebo- controlled study with 796 obese patients. 212 received the placebo, 213 received 60-mg Xenical three times per day, and 210 received 120-mg Xenical three times per day. The weights of the participants were recorded at 52 weeks and at 104 weeks.

            At the end of the study, the dropout rates were extremely high. They were 57.1%, 44.1%, and 46.2% respectively. As reported, the average weight losses per group were as follows: 9.37 pounds at 52 weeks and 3.39 pounds at 104 weeks in the placebo group, 17.42 lbs at 52 weeks and 10.08 lbs at 104 weeks in the 60-mg group, and 19.32 lbs at 52 weeks and 11.35 lbs at 104 weeks in the 120-mg group. The adverse side effects that were reported in 20-25% of the patients were fecal urgency, oily spotting, fatty stools, and flatulence. The weight loss did cause the total cholesterol level to decrease, but it was concluded that the decrease in the LDL cholesterol levels, which were about the same in both Xenical groups, was more likely to be dependent upon another effect of Xenical other than it’s weight loss properties.

            In conclusion, the researchers agreed that it would be unlikely that the Xenical would meet the treatment expectations of the patients and physicians.

            In Stockholm, Sweden, Professor Stephan Rossner decided that he would look into the long term benefits of Xenical on weight- loss and obesity related risk factors. He and his researchers performed a two- year randomized, double- blind, placebo- controlled study on this drug. Obese patients were placed randomly into either the Xenical group or the placebo group. The first year the participants ate a hypocaloric diet and the second year they ate a weight maintenance diet. This was to test for regain of weight. Changes in body weight, fat profiles, glycemic control, blood pressure, and overall quality of life were monitored.

                Their results suggest that patients in the Xenical group lost significantly more weight and experienced less weight gain, than the control group. They also improved in the group of obesity related risk factors and overall quality of life.

            Many interactions between Xenical and other drugs have also been studied. In Switzerland, Hartmann, et al., looked at the interactions between Xenical and the ovulation- suppressing action of oral contraceptives. After measuring the levels of hormones active in a menstrual cycle, he determined that Xenical did not have any influence or interaction with oral contracepives.

            Other researchers in Switzerland looked at interaction between Xenical and ethanol in volunteers. They found that the ingestion of ‘social’ amounts of ethanol did not alter the effects of Xenical.

            Many different groups of people have looked into the effects of the new dietary drug Xenical. And from all sides it seems as if there is enough evidence to safely recommend this drug to obese patients who are looking for a way to lose weight. The main drawback of this drug is the gastrointestinal side effects, which should not be that harmful. As long as the prescription is followed and as long as the extra vitamins are taken, it seems as if this drug could be a breakthrough in helping to combat the increasing problems with obesity… as long as you and your friends can ignore the side effects.





Hartmann, D., Guzelhan, C., Zuiderwijk, P., Odink, J. Lack of interaction between orlistat and oral contraceptives. TNO Nutrition and Food Research. 1996; 50 (5):421-4.


Hauptman, J., et al. Orlistat in the long- term treatment of obesity in primary care settings. Arch Family Med. 2000; 9: 160-7.


Melia, A.T., Zhi, J., Zelasko, R., Hartmann, D., Guzelhan, C., Guericiolini, R., Odink, J. Pharmacokinetics and disposition: The interaction of the lipase inhibitor orlistat with ethanol in healthy volunteers. TNO Nutrition and Food Research. 1998; 54 (9-10):773-7.


Rossner, S., Sjostrom, L., Noack, R., Meinders, A., Noseda, G. Weight loss, weight maintenance, and improved cardiovascular risk factors after two years treatment with orlistat for obesity. Obesity Research. 2000; 8: 49-61.




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