There are well-established regional differences in obesity prevalence in the U.S., but relatively little is known about whether these differences impact efforts for weight loss. The objective of the study was to determine whether changes in body weight, engagement in physical activity (PA), and psychosocial factors differed in Colorado (CO) vs Alabama (AL) in response to a 16-week standardized behavioral weight management program. We hypothesized that weight loss would be greater in Colorado due to a more favorable physical and social environment.
This is an ancillary study to a weight loss intervention being conducted simultaneously in AL and CO with identical intervention content and delivery. Study participants (n = 70, 39 CO, 31 AL) were randomized to either a high protein (HP) or normal protein (NP) diet for 16 weeks and attended weekly group classes led by a trained coach targeting diet, mindset, and physical activity. Body weight, objective (accelerometry) and self-reported (International Physical Activity Questionnaire) PA, and responses to psychosocial questionnaires were collected at baseline and week 16. Psychosocial constructs included executive function, hedonic eating, stress, and social support.
Both states lost a significant amount of weight (CO 13.2 ± 4.9 kg P = 0.0067; AL 12.5 ± 5.6 kg P = 0.0262) with no differences between states (P = 0.9315). Both states improved in all PA outcomes over time, with AL increasing significantly more in objective PA measures when compared to CO. AL had more favorable scores for hedonic eating at baseline (23.2 ± 2.4 vs 32.5 ± 1.8, P = 0.0017), which persisted to week 16 (19.0 ± 2.7 vs 29.7 ± 2.2, P = 0.0021). Finally, AL improved in several social support factors while CO did not.
While weight loss did not differ between states, AL experienced greater improvements in some factors known to improve long-term weight loss maintenance. Results from this study provide a strong rationale for investigating potential regional differences in the maintenance of lost weight that may not be apparent during the active weight loss phase of interventions. Future research in this area will require effective methods for tracking participants beyond the conclusion of most clinical trials.
The parent clinical trial is supported by The Beef Checkoff.