Intermittent vs Continuous Energy-Restricted Diet: Effects on Glycemic Control and Weight Loss T2D
Intermittent energy restriction followed a diet of 500 to 600 kcal/day for 2 days of the week and then a usual diet for the remaining 5 days.
According to a study published in JAMA Network Open, intermittent energy restriction is an effective alternative diet strategy for reducing HbA1c in patients with type 2 diabetes and is comparable to continuous energy restriction.
To determine whether intermittent energy restriction offers similar glycemic control benefits as continuous energy restriction, researchers conducted a randomized noninferiority trial in which 137 adults with type 2 diabetes (mean age, 61.0 years) were assigned to parallel diet groups. Baseline characteristics were comparable between the 2 groups.
For 12 months, 70 participants adhered to an intermittent energy restriction diet, restricting themselves to 500 to 600 kcal/day for 2 nonconsecutive days per week, followed by 5 days of their usual diet. Sixty-seven participants adhered to a continuous energy restriction diet (1200-1500 kcal/day) every day for the same period.
All outcomes were measured at baseline and at 3 and 12 months. The primary outcome was change in HbA1c level, and the secondary outcome was change in body weight. Intention-to-treat analysis revealed similarly significant mean reductions in HbA1c: −0.5% for continuous restriction and −0.3% for intermittent restriction (P =.65). Weight change was also comparable with those in the intermittent energy restriction group, losing an average of 6.8 kg, and those in the continuous energy restriction group, losing an average of 5.0 kg (P =.25).
As for exploratory outcomes, researchers found no significant difference between groups in regard to final step count, fasting glucose levels, lipid levels, and total medication effect score.
Researchers noted several limitations to their study. Most notably, generalizability was restricted because the sample population had well-controlled type 2 diabetes.
Despite these limitations, researchers concluded, "Intermittent energy restriction is safe for people who have either diet-controlled type 2 diabetes or are using medication that is not likely to cause hypoglycemia. For people using sulfonylureas and/or insulin, intermittent energy restriction requires medication changes and regular monitoring, especially in the initial stages."
Carter S, Clifton PM, Keogh JB. Effect of intermittent compared with continuous energy restricted diet on glycemic control in patients with type 2 diabetes. JAMA Network Open. 2018;1(3):e180756.