myDIDeA was a 12-months two-armed randomised controlled trial conducted in three tertiary public hospitals in Klang Valley, Malaysia. The primary outcome was the Dietary Knowledge, Attitude and Behaviour (DKAB) score, while the secondary outcomes included measures of food intake, anthropometry measurements, blood pressure and resting heart rate, some blood biomarkers and the Dietary Stages of Change (DSOC) score. The study was designed according to the recommendations of the CONSORT statement for randomised trials of non-pharmacologic treatment. The study commenced in November 2009 after obtaining the ethical approvals from relevant authorities, and the trial has been registered with Clinicaltrials.gov (NCT01246687). After being screened for eligibility, 128 patients with Type 2 Diabetes Mellitus (T2DM) from the outpatient clinics at these hospitals were recruited with informed consent, and then randomised into the e-intervention (n=66) or the control (n=62) group. The e-intervention group received an intensive six-month dietary intervention through the study website, which was developed based on various established guidelines and recommendations but personalised according to the participants’ DSOC, in addition to the usual standard treatment at the outpatient clinics. In contrast, the control group continued their usual standard treatment for patients with T2DM in the hospitals. Data were collected at baseline, six months post-intervention and at 12 months follow-up. A pre-tested and validated questionnaire was used for this purpose. The anthropometry measurements, blood pressure and resting heart rate were measured at data collection, while details on the blood biomarkers were obtained from the hospital medical records. All data were analysed with IBM® PASW® Statistics 17.0. On average, each participant logged into the website once a week and spent 11 minutes at the website per visit. myDIDeA was found to be a successful intervention programme to improve the overall DKAB score, due to the improvement in the knowledge and attitude sub-domains. Additionally, the intervention programme also successfully improved the DSOC score of the intervention group, which suggests participants were also making small but significant progress in changing their dietary behaviour. Some additional improvements in diet quality (reduction in carbohydrate and protein intake), glycaemic control and total cholesterol were also detected. myDIDeA is one of few web-delivered dietary interventions for patients with chronic disease. The reach, flexibility, accessibility and conversion of established guidelines into a more user-friendly format have contributed to the success of this intervention programme. Future related studies are suggested to emphasise on the interactivity, familiarise the participants with the system prior to the intervention, encourage self-monitoring and built the intervention on a strong theoretical background.