After 6 months, the group receiving medication had lost
4.6 kg (about 10 pounds) more than the control group. But during the second half of the study, when both groups received sibutramine, the results were more ambiguous. In months 6-12, the group that continued to take sibutramine gained an average of 0.8 kg, or roughly 2 pounds; the control group, which switched from placebo to sibutramine, lost 1.3 kg, or roughly 3 pounds
(p. 1808). Both groups received behavioral therapy covering diet, exercise, and mental health.
These results paint a murky picture of the effectiveness of the medication: While initial data seemed promising, the results after one year raised questions about whether medication-induced weight loss could be sustained over time. As Berkowitz et al. (2003) advised, “Until more extensive safety and efficacy data are available, . . . weight-loss medications should be used only on an experimental basis for adolescents” (p. 1811).
A study testing the effectiveness of orlistat in adolescents showed similarly ambiguous results. The FDA approved orlistat in 1999 but did not authorize it for adolescents until December 2003. Roche Laboratories (2003), maker of orlistat, released results of a one-year study testing the drug on 539 obese adolescents, aged 12-16. The drug, which promotes weight loss by blocking fat absorption in the large intestine, showed some effectiveness in adolescents: an average loss of 1.3 kg, or roughly 3 pounds, for subjects taking orlistat for one year, as opposed to an average gain of 0.67 kg, or 1.5 pounds, for the control group (pp. 8-9). See Table 1