Introduction: Reversal of type 2 diabetes (T2D) using a very low energy diet (VLED) has been demonstrated in adults but has not been studied prospectively in youth.

Objective: To investigate whether rapid weight loss associated with short-term severe energy restriction resulted in reversal of T2D in youth.

Methods: We recruited eight participants with T2D, aged 7-16 years. Participants followed a VLED (3 Optifast meal replacements and a low-carbohydrate meal, ~800kcal/day) for 8-weeks. Over a 2-4 week period, participants transitioned to an individualised hypocaloric diet (~1500kcal) which they followed to 34-weeks. HbA1c, fasting glucose and 2-hr glucose (2hG) were determined from fasting blood and oral glucose tolerance tests. Intrahepatic triglyceride (IHTG) was quantified using magnetic resonance spectroscopy. Adherence was defined as ≥5% weight loss during the 8-week VLED.

Results: Adherers (n=5) and non-adherers (n=3) had a median weight loss of 7.5% and 0.5% respectively during the 8-week VLED. Overall, HbA1c (mean[SD]: 8.1[2.1]% to 6.6[1.3]%, P=0.004) and 2hG (15.6[4.6]mmol/L to 11.3[2.8]mmol/L, P=0.009) were significantly reduced at 8 weeks compared with baseline. IHTG also significantly reduced from baseline (14.7[2.2]%) to 8-weeks (5.8[1.7]%, P=0.001); only 3/8 participants met non-alcoholic fatty liver disease (NAFLD) criteria (IHTG≥5.5%) at 8-weeks compared with 8/8 at baseline. Non-adherers dropped out during follow-up. All five adherers completed the study with a median weight loss of 12.3%, none met NAFLD criteria and four no longer met the American Diabetes Association criteria for T2D at 34-weeks.

Conclusions: Adherence to a VLED can lead to rapid weight loss, dramatic reductions in IHTG and the reversal of T2D in youth, at least short-term. This highlights the capacity of a VLED to be used as first-line treatment in youth with newly diagnosed T2DM. A larger trial with a control group and longer follow-up may be required to encourage a change in clinical practice.