The study by Williams et al. (2000) investigates the role of autonomous motivation in weight loss and weight loss maintenance among severely obese patients. Using a 6-month, very-low-calorie weight-loss program with a 23-month follow-up, the researchers tested the predictions of self-determination theory, which posits that behavior change is more likely to occur and persist if it is autonomously motivated. The study found that participants with more autonomous motivation for weight loss attended the program more regularly, lost more weight during the program, and maintained greater weight loss at the follow-up. Autonomous motivation was predicted by both individual differences in autonomy orientation and the perceived autonomy supportiveness of the interpersonal climate created by healthcare staff. The study also confirmed that health locus of control did not predict weight loss or maintenance, supporting the importance of autonomous motivation over external control. The findings highlight the significance of autonomous motivation in the success of weight-loss programs and the role of healthcare staff in fostering an autonomy-supportive environment.The study by Williams et al. (2000) investigates the role of autonomous motivation in weight loss and weight loss maintenance among severely obese patients. Using a 6-month, very-low-calorie weight-loss program with a 23-month follow-up, the researchers tested the predictions of self-determination theory, which posits that behavior change is more likely to occur and persist if it is autonomously motivated. The study found that participants with more autonomous motivation for weight loss attended the program more regularly, lost more weight during the program, and maintained greater weight loss at the follow-up. Autonomous motivation was predicted by both individual differences in autonomy orientation and the perceived autonomy supportiveness of the interpersonal climate created by healthcare staff. The study also confirmed that health locus of control did not predict weight loss or maintenance, supporting the importance of autonomous motivation over external control. The findings highlight the significance of autonomous motivation in the success of weight-loss programs and the role of healthcare staff in fostering an autonomy-supportive environment.