Promoting weight loss and psychological well-being in patients with obesity: A sequential combination of behavioural lifestyle intervention and well-being therapy.

Behavioural lifestyle interventions focused on diet and physical activity are a cornerstone for the treatment of obesity. However, their effects vary substantially across individuals in terms of magnitude and durability. Personalized approaches that target psychological well-being may be promising to facilitate healthy behaviours and sustained weight loss. This preliminary study aimed to explore whether the sequential combination of behavioural lifestyle intervention (BLI) and well-being therapy (WBT) may result in more favourable outcomes than BLI alone in promoting weight loss (primary outcome) and improving psychological well-being, distress, dietary behaviours and physical activity (secondary outcomes). A total of 83 patients with obesity were randomly assigned to BLI/WBT (N = 38) or BLI group (N = 45). The BLI group received a 12-week behavioural weight loss programme, whereas the BLI/WBT group received the same programme followed by an additional 4-week WBT, adapted for group interventions. Data were collected at pretreatment (baseline, T1), at the end of BLI/WBT (T2), at 6-month (T3) and 12-month (T4) follow-ups. There was a significant weight loss in both treatment groups at T2, T3 and T4. The BLI/WBT group showed greater improvements in depressive symptoms at T3 and T4, in autonomy at T2, in personal growth at T4 and in global well-being at T4 compared with BLI group. WBT yielded no additional effect on weight loss. However, the secondary outcomes indicate that WBT may have enduring effects that reduce vulnerability to psychological distress in patients with obesity. In order to confirm these preliminary findings and explore whether a more intensive and individualized WBT can foster sustained weight loss, future studies are needed.