Prioritizing multiple health behavior change research topics: expert opinions in behavior change science

Moderators of a Diet and Physical Activity Intervention: who Responds Best to Sequential vs. Simultaneous Approaches

BACKGROUND

Given that low physical activity levels and poor dietary intake are co-occurring risk factors for chronic disease, there is a need for interventions that target both health behaviors, either sequentially or simultaneously. Little is known about participant characteristics that are associated with better or worse response to sequential and simultaneous interventions.

METHOD

The 12-month Counseling Advice for Lifestyle Management (CALM) randomized trial (N = 150; Mage = 55.3 years) targeted these two behaviors either via a sequential approach - dietary advice first then exercise advice added ("Diet-First") or exercise advice first then dietary advice added ("Exercise-First") - or via a simultaneous approach. The objective was to examine demographic, clinical, and psychosocial moderators of intervention effects on 12-month change in (1) moderate-to-vigorous physical activity (MVPA), (2) fruit/vegetable intake, (3) caloric intake from saturated fat, and (4) weight. Hierarchical regressions first compared Diet-First to Exercise-First, followed by comparisons of these arms combined ("sequential") to the simultaneous arm.

RESULTS

Older age, higher baseline BMI, and lower social support were associated with higher MVPA in Exercise-First vs. Diet-First, while lower tangible support was associated with higher fruit/vegetable intake in Exercise-First but not in Diet-First. Poor sleep was associated with higher levels of MVPA in the sequential arm than in the simultaneous arm. Lower vitality was associated with greater weight loss in the sequential arm than in the simultaneous arm, while the opposite was true for those who were not married.

CONCLUSION

Identifying moderators of treatment response can allow the behavioral medicine field to enhance intervention efficacy by matching participant subgroups to their best-fitting interventions.

TRIAL REGISTRATION

NCT00131105.

A web-based lifestyle intervention program for Chinese college students: study protocol and baseline characteristics of a randomized placebo-controlled trial

Background

This study aimed to describe the design and present the baseline characteristics of a web-based lifestyle intervention program, which comprises of sequentially and simultaneously delivered intervention modules targeting physical activity (PA) and fruit and vegetable consumption (FVC) in Chinese college students.

Methods

The study adopted a randomized placebo-controlled trial, using the Health Action Process Approach (HAPA) and the Compensatory Carry-Over Action Model (CCAM) as the theoretical backdrops. 556 Chinese college students participated in the 8-week web-based lifestyle intervention program. All eligible participants were randomly assigned to one of four groups: 1) the PA-first arm which received a 4-week intervention addressing PA followed by a 4-week intervention addressing FVC; 2) the FVC-first arm which received a 4-week intervention addressing FVC followed by a 4-week intervention addressing PA; 3) the PA + FVC simultaneous arm that received an 8-week intervention addressing both PA and FVC at the same time; and 4) the placebo-control arm that received 8 weeks of general health information, which is not relevant for changing actual PA and FVC behaviors. Data collection includes four time-points: at the beginning and end of the intervention, and a 3-month and 12-month follow-up after the intervention.

Results

At baseline, 41.7% of participants were male and 58.3% were female. 41.0% of the participants did not meet the standard PA-recommendations, while 69.6% did not adhere to the standard FVC-recommendations. In total, only 19.6% of participants met both PA and FVC recommendations. Baseline characteristics across the four groups had no significant differences (all P = .17–.99), indicating successful randomization.

Conclusions

The preliminary results indicate a high prevalence of unhealthy lifestyles in college students in China, which further supports the need for web-based health intervention programs. This is also the first study that examines the comparative effectiveness of simultaneously and sequentially delivered lifestyle interventions in the Chinese population. These findings may contribute to the creation of future web-based health behavior change interventions.

Trial registration

ClinicalTrails.gov: NCT03627949, 14 August, 2018.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7438-1) contains supplementary material, which is available to authorized users.