Effect of a web-based behavior change program on weight loss and cardiovascular risk factors in overweight and obese adults at high risk of developing cardiovascular disease: Randomized controlled trial

Background: web-based programs are a potential medium for supporting weight loss because of their accessibility and wide reach. research is warranted to determine the shorter- and longer-term effects of these programs in relation to weight loss and other health outcomes. objective: the aim was to evaluate the effects of a web-based component of a weight loss service (imperative health) in an overweight/obese population at risk of cardiovascular disease (cvd) using a randomized controlled design and a true control group. methods: a total of 65 overweight/obese adults at high risk of cvd were randomly allocated to 1 of 2 groups. group 1 (n=32) was provided with the web-based program,which supported positive dietary and physical activity changes and assisted in managing weight. group 2 continued with their usual self-care (n=33). assessments were conducted face-to-face. the primary outcome was between-group change in weight at 3 months. secondary outcomes included between-group change in anthropometric measurements,blood pressure,lipid measurements,physical activity,and energy intake at 3,6,and 12 months. interviews were conducted to explore participants' views of the web-based program. results: retention rates for the intervention and control groups at 3 months were 78% (25/32) vs 97% (32/33),at 6 months were 66% (21/32) vs 94% (31/33),and at 12 months were 53% (17/32) vs 88% (29/33). intention-to-treat analysis,using baseline observation carried forward imputation method,revealed that the intervention group lost more weight relative to the control group at 3 months (mean -3.41,95% ci -4.70 to -2.13 kg vs mean -0.52,95% ci -1.55 to 0.52 kg,p<.001),at 6 months (mean -3.47,95% ci -4.95 to -1.98 kg vs mean -0.81,95% ci -2.23 to 0.61 kg,p=.02),but not at 12 months (mean -2.38,95% ci -3.48 to -0.97 kg vs mean -1.80,95% ci -3.15 to -0.44 kg,p=.77). more intervention group participants lost ≥5% of their baseline body weight at 3 months (34%,11/32 vs 3%,1/33,p<.001) and 6 months (41%,13/32 vs 18%,6/33,p=.047),but not at 12 months (22%,7/32 vs 21%,7/33,p=.95) versus control group. the intervention group showed improvements in total cholesterol,triglycerides,and adopted more positive dietary and physical activity behaviors for up to 3 months verus control; however,these improvements were not sustained. conclusions: although the intervention group had high attrition levels,this study provides evidence that this web-based program can be used to initiate clinically relevant weight loss and lower cvd risk up to 3-6 months based on the proportion of intervention group participants losing ≥5% of their body weight versus control group. it also highlights a need for augmenting web-based programs with further interventions,such as in-person support to enhance engagement and maintain these changes. trial registration: clinicaltrials.gov nct01472276; http://clinicaltrials.gov/ct2/show/study/nct01472276 (archived by webcite at http://www.webcitation.org/6z9lfj8nd). ©sinead watson,jayne v woodside,lisa j ware,steven j hunter,alanna mcgrath,christopher r cardwell,katherine m appleton,ian s young,michelle c mckinley.