Exclusion Criteria

People with any other current significant medical condition or undergoing medical treatment that is likely to significantly affect weight, or which makes weight loss or dietary restriction a contraindication including: a. people with uncontrolled diabetes or hypothyroidism b. severe psychiatric symptoms, including mania and psychosis, which would interfere with ability to participate in this study c. significant current risk of suicidality or homicidality d. currently being prescribed any medications that are known to significantly increase or decrease weight including oral steroids, antiobesity medications, antipsychotics and the mood-stabilising medications sodium valproate and lithium carbonate e. pregnant, lactating, trying or planning to get pregnant in the near future or refusal to use a reliable method of birth control in female participants f. insufficient intellectual or educational capacity to complete the programme based on clinical assessment, or insufficient command of the English language to participate adequately in the therapeutic programme. g. with severe physical disability impeding their ability to undertake the Two Minute Step in Place Test.