> In other words, they got worse. “They had gained unhealthy weight,” explained Signe Sørensen Torekov, professor of biomedical sciences at the University of Copenhagen and lead author of the study. On the other hand, the people who had continued to exercise on their own were able to better maintain their weight and preserved more muscle mass. The results clearly indicate that people taking these drugs can “maintain a healthy weight” even after stopping the medication. “But they need to exercise,” Torekov added.
That does not follow, because this is simply yet another correlational result: the selective attrition after randomization is not itself randomized and therefore can be confounded. It is also possible that the people who got sicker or unhealthier after stopping the useful drug then stopped exercise.
(It is, in fact, not just possible, but must be the case to at least some degree: unless you want to argue that getting unhealthier would have no impact on whether you were able & willing to keep exercising...? Regardless of whether exercise has any effect, sick or fat people find it harder to exercise, and so would do it less than healthy or thin people.)
That does not follow, because this is simply yet another correlational result: the selective attrition after randomization is not itself randomized and therefore can be confounded. It is also possible that the people who got sicker or unhealthier after stopping the useful drug then stopped exercise.
(It is, in fact, not just possible, but must be the case to at least some degree: unless you want to argue that getting unhealthier would have no impact on whether you were able & willing to keep exercising...? Regardless of whether exercise has any effect, sick or fat people find it harder to exercise, and so would do it less than healthy or thin people.)