The research team also carried out a study on the predictors of successful weight loss on orlistat, using 566 patients. All completed a questionnaire at the start and after six months concerning their weight, beliefs, and behaviors.
After six months, three-quarters of patients had lost some weight and the majority showed improvements in healthy eating. Many had also stopped taking orlistat and a large minority reported using flexibly in response to their dietary choices.
The patients who lost the most weight after six months had “a greater endorsement of a medical solution to obesity” at the start of treatment, meaning that those who have higher expectations of success for the drug went on to have greater success.
When the patients’ changes in beliefs and behavior over the course of taking orlistat were analyzed, results showed that those who lost the most weight showed a decrease in belief in a medical solution; a decrease in unhealthy eating; an increased belief in treatment control; and an increased belief that the side effects are both due to their eating behavior and just part of how the drug works.
“It would seem that taking orlistat may encourage patients to focus on their behavior rather than medical factors as solutions to obesity,” the team writes in the Journal of Obesity. If such changes in beliefs occur alongside improvements in diet, a patient’s weight loss is greater.
“This indicates that the side effects of orlistat, while being unpleasant and a deterrent for some users, may help educate others towards a more behavioral focus on their weight problem,” the team writes.
They conclude that, although research indicates that orlistat can promote weight loss, “there remain problems with adherence and much variability in patient outcomes. Our results indicate that changes in beliefs and behavior occurring throughout the course of taking orlistat are the best predictors of outcomes, rather than baseline variables.”
“Further, the results indicate that those patients who show a shift away from a medical model of their problem towards a focus on their own behavior and show improvements in their diet, lose more weight.”
The researchers suggest that these results could be useful for patient management. The unpleasant side effects caused by orlistat may lead to nonadherence, but “rather than conceptualizing such side effects as unfortunate, they may be the very ‘active’ ingredients necessary to bring about change in patients’ behavior.”
“When prescribing orlistat, clinicians should encourage patients to focus and learn from the side effects in terms of what they are eating. Such an emphasis may encourage patients to see these consequences of the drug as an education, thus enabling them to take more ownership of their weight problem, in turn facilitating and promoting changes in eating behavior.”