The effect of intermittent energy restriction on weight loss and diabetes risk markers in women with a history of gestational diabetes: a 12-month randomized control trial

Weight loss after gestational diabetes (GDM) can prevent or delay the onset of type 2 diabetes. Intermittent energy restriction (IER) may offer an alternative to continuous energy restriction (CER) for weight loss. We compared the effects of IER (2 days per week) to daily CER over 12 mo on weight loss and diabetes risk markers in overweight women with previous GDM. Overweight females (n = 121) ≥18 y were randomized 1:1 to either IER [2-d 500 kcal (2100 kJ); n = 61] or CER [1500 kcal (6000 kJ); n = 60] in this 12-mo noninferiority trial. The trial was completed by 62 participants with a median age of 39.6 y [Quartile (Q) 1 to Quartile 3, 34.9 to 43.9 y] with a median BMI of 32.6 kg/m2 (Q1 to Q3, 28.5 to 37.9 kg/m2) at a median of 2.9 y after GDM (Q1 to Q3, 2.1 to 6.4 y; 49% attrition; IER n = 29; CER n = 30; P = 0.8). The mean ± SD weight loss was significant over time (P < 0.001) but not by diet group (IER −4.8 ± 5.0 kg; CER −3.2 ± 5.0; P = 0.2). The mean between-group difference was −1.6 kg (95% CI: −4.2 to 1.0 kg; P = 0.2). There were no significant between-group differences in change in HbA1c, fasting plasma glucose, fasting serum insulin, HOMA-IR or 2-h oral glucose tolerance at 12 mo (p>0.05). The trial was registered at https://www.anzctr.org.au/ (ACTRN12617001476325). IER produces comparable weight loss to CER over 12 mo in overweight women with previous GDM. The high dropout rate in this study is a limitation in the interpretation of these results. Larger studies are needed to confirm noninferiority of IER compared to CER.