Intermittent energy restriction (IER) is a popular alternative weight loss method, however, to date, there are no long-term trials in patients with type 2 diabetes (T2DM). The aim of this trial was to investigate the effects of IER compared with continuous energy restriction (CER) on glycaemic control and weight loss in patients with T2DM over 12-months. One hundred and thirty seven (61 ± 9 years) overweight or obese participants (BMI 36 ± 6kg/m2) with T2DM (HbA1c 7.3 ± 1.3%) were randomised to either a 2-day IER diet (2100-2500kJ/d), during which participants followed their usual diet for the other 5 days, or a CER diet (5000-6270kJ/d) followed daily for 12 months. Medications likely to cause hypoglycemia were reduced at baseline according to the medication management protocol. Of the 137 randomised participants, 97 participants completed the trial. Intention-to-treat analysis showed similar reductions in HbA1c (-0.5 ± 0.2% CER, -0.3 ± 0.1% IER; P=.65) with a between-group difference of 0.2% (90% CI, -0.2% to 0.5%) meeting the criteria for equivalence (±0.5%). Weight change was similar between groups (-5.0 ± 0.8kg CER, -6.8 ± 0.8kg IER; P=.25) with a between-group difference of -1.8kg (90% CI, -3.7kg to 0.07kg) which did not meet the criteria for equivalence (±2.5kg). There were no significant differences between groups in changes to body composition, final step count, fasting glucose, lipids or total medication effect score at 12 months. Effects did not differ using completers analysis. Hypoglycaemic or hyperglycaemic events in the first 2 weeks of treatment were similar between groups (3.2 ± 0.7 events CER, 4.9 ± 1.4 events IER; P=.28), affecting 35% of participants using either sulphonylureas and/or insulin. Intermittent energy restriction is an effective alternative diet strategy for HbA1c reduction comparable to CER in patients with T2DM and may be superior for weight loss.