Obesity during childhood and youth has reached epidemic proportions (WHO, 2000). Inaddition to the long-term health risks, obesity during childhood and youth is associated withmultiple adolescent health problems ranging from type-2 diabetes to depression (Lobsteinand Jackson, 2007). Being overweight during youth is also associated with a range ofadverse psychosocial outcomes including lower self-esteem (Griffiths et al., 2010). Obesityis now seen as a health and economic ‘time bomb’ (Department of Health, 2002) with thedirect costs to the NHS already estimated to be over £5 billion per year (Scarborough et al.,2011).