Immediately after surgery has been undertaken, BARI-LIFESTYLE Observational Study participants will be randomised to continue to receive usual care, or usual care plus lifestyle intervention (nutritional and behavioural tele-counselling, self-monitoring and a 12-week supervised tailored exercise programme). However, to avoid contamination between the intervention group and the usual care group, only those randomly allocated to the lifestyle intervention group will be informed of this. They will be given a PIS (BARI-LIFESTYLE Intervention Study) and informed consent will be sought. If the participants decline to take part in the lifestyle programme, they will remain in the control group (observational cohort study).