Adolescent obesity is associated with both short and long term complications including type 2 diabetes, related comorbidities and premature mortality. Lifestyle modification is the first line of treatment. However, which is the best diet remains unclear. Emerging evidence indicates that the primary objective of dietary interventions should be to reduce the total energy intake and the most successful diet will be the one that the patient will adhere. Current recommendations involve moderate daily energy restriction. Yet several studies, including our recent randomised control trial, RESIST, indicate that some young people struggle to benefit from this type of diet. Alternative options are required.
We are currently investigating the use of severe energy restriction (very low energy diets; VLED) and intermittent fasting, in obese adolescents. The VLED are targeted at adolescents at high risk of, or have been diagnosed with type 2 diabetes. Current treatment of type 2 diabetes is generally management of hyperinsulinemia and hyperglycaemia. However, in adults the abnormalities underlying type 2 diabetes, including normalising insulin secretion have been reversed by short term use of a VLED; changes which can be maintained up to 18 months even after some weight regain. The VLED diet is tough; yet this approach has the potential to reverse type 2 diabetes and provides an alternative to pharmacological therapies and surgical options. Intermittent fasting incorporates ‘fasting’ days (~25% energy requirements) and ‘feeding’ days and has been popularised by the 5:2 diet. Short term studies in adults indicate that intermittent ‘fasting’ is as effective in decreasing body weight as daily energy restriction and may be superior in preserving fat free mass and improving metabolic profile. Preliminary findings from our research and clinical experience with these diets will be presented.