Applicability of the New Zealand-eating behavior questionnaire to predict weight loss responses to naltrexone/bupropion: a proof-of-concept trial.

BACKGROUND

Despite the availability of different obesity medications, individual responses vary widely. This pilot study evaluated whether the New Zealand Eating Behavior Questionnaire (NZ-EBQ) could predict weight loss response to naltrexone/bupropion in adults with clinical obesity.

METHODS

We conducted a 24-week prospective, single-site, pilot, exploratory, phenotype-stratified trial evaluating utility of the NZ-EBQ for predicting weight reduction response to naltrexone/bupropion. Prior to enrolment, participants completed the NZ-EBQ, which classified their eating behavior phenotype and hypothesized congruence or incongruence with treatment allocation. The primary outcomes were changes in body weight and body mass index (BMI) at 12 and 24 weeks between emotional eaters and other phenotypes (reduced satiety or satiation) tested using independent t-tests and linear regression (significance threshold p < 0.10).

RESULTS

Of 67 participants enrolled, 44 (65.7 %) completed 12 weeks and 37 (55.2 %) completed 24 weeks. Median baseline weight was 133.1 kg (IQR: 111.6-151.7). At 24 weeks, mean weight loss was 4.54 % (95 % CI: 2.83-6.25 %). Participants with emotional eating lost significantly more weight (6.44 %, 95 % CI: 3.64-9.24) than those with reduced satiation (4.69 %, 95 % CI: 0.23-9.15) or reduced satiety (2.82 %, 95 % CI: 0.33-5.30). In multiple linear regression analysis, primary eating behavior trait score and family history of obesity were significant predictors of weight loss (B = 16.8, SE = 10.9, p = .13, 95 % CI: 5.59 - 39.15). The safety profile, including rate of withdrawal and treatment-related adverse events, was consistent with results reported in pivotal studies with naltrexone/bupropion.

CONCLUSION

These findings suggest that participants with emotional eating lost more weight after naltrexone/bupropion than those with other eating behavior phenotypes identified using the NZ-EBQ. Further trials are warranted to validate these preliminary results.Australia and New Zealand Clinical Trials Registry (ACTRN12622000703707).