Design and Procedure
The present study employed a 2 (Condition: intervention vs. control) by
2 (Time: preintervention vs. 8-week post-intervention) mixed measure
design, with Time a repeated measure factor. A power calculation was
undertaken using G*power 3.1 software
(Faul et al., 2009), whereby a repeated
measure MANOVA is used with a power of 80%, an effect size of 0.4 and
α=0.05, yielding a minimum sample size required of 97 participants (that
was minimally exceeded following exclusions, etc.). A total of 220
adults diagnosed with T2D were selected from a list provided by IDS
using permuted block randomization (a 1:1 allocation ratio) and
contacted. As a result, the exclusion could only take place after the
randomization process. Permuted block pattern was obtained via an
Internet-generated pattern with a block size of 8. The participant’s
list was provided by IDS staff, and the researchers were blinded. Figure
1 shows the flow of participants in the study. Written informed consent
was obtained from each participant before the experiment. The study
conforms to CONSORT guidelines (Schulz et
al., 2010) (see Supplementary File 1).