BACKGROUND:Increasing prevalence and disease burden has led to an increasing demand of programs and studies focused on dietary and lifestyle habits, and chronic diseases such as type 2 diabetes mellitus (T2DM). We evaluated the effects of a 6-month web-based dietary intervention on Dietary Knowledge, Attitude and Behaviour (DKAB), Dietary Stages of Change (DSOC), fasting blood glucose (FBG) and glycosylated haemoglobin (HbA1c) in patients with uncontrolled HbA1c (> 7.0%) in a randomised-controlled trial (myDIDeA) in Malaysia. METHODS:The e-intervention group (n = 62) received a 6-month web-delivered intensive dietary intervention while the control group (n = 66) continued with their standard hospital care. Outcomes (DKAB and DSOC scores, FBG and HbA1c) were compared at baseline, post-intervention and follow-up. RESULTS:While both study groups showed improvement in total DKAB score, the margin of improvement in mean DKAB score in e-intervention group was larger than the control group at post-intervention (11.1 ± 0.9 vs. 6.5 ± 9.4,p < 0.001) and follow-up (19.8 ± 1.1 vs. 7.6 ± 0.7,p < 0.001), as compared to the baseline. Although there was no significant difference between intervention and control arms with respect to DSOC score and glycaemic control, the e-intervention group showed improved DSOC score (199.7 ± 18.2 vs193.3 ± 14.6,p = 0.046), FBG (7.9 ± 2.5 mmol/L vs. 8.9 ± 3.9 mmol/L,p = 0.015) and HbA1c (8.5 ± 1.8% vs. 9.1 ± 2.0%,p = 0.004) at follow-up compared to the baseline, whereas such improvement was not seen in the control group. CONCLUSIONS:Most important impact of myDIDeA was on the overall DKAB score. This study is one of the first to demonstrate that an e-intervention can be a feasible method for implementing chronic disease management in developing countries. Concerns such as self-monitoring, length of intervention, intense and individualized intervention, adoption of other domains of Transtheoretical Model and health components, and barriers to change have to be taken into consideration in the development of future intervention programs. TRIAL REGISTRATION:ClinicalTrials.gov NCT01246687 .