Outcome measures and time points at which they were taken

Baseline demographic and clinical characteristics
 Age, sex, educational level, smoking statusX
 Manipulation checkXX
 Working memory spanXX
 Number of completed sessionsXX
Primary outcome measures
 Cambridge Neuropsychological Test Automated Battery#XXXX
 Addenbrooke's Cognitive Examination-RevisedX
Secondary outcome measures
 Physical capacity and activity
  6-min walk testXXX
  Short Physical Performance BatteryXXX
 Dietary intake
  Alternative Healthy Eating Index-2010XXX
 Cognitive stress susceptibility and perception
  Cortisol Awakening ResponseXX
  Perceived Stress ScaleXXX
  Socially Evaluated Cold Pressor TestXXX
 Healthy lifestyle goal recallXX
Exploratory outcome measures
 Healthy lifestyle motivation
  Behavioural Regulation of Exercise Questionnaire-2XX
  Regulation of Eating Behaviours ScaleXX
 Psychological wellbeing
  Beck Depression Inventory-IIXXX
  Generalised Anxiety Disorder-7XXX

T0: baseline minus 1 week; T1: baseline; T2: after the first phase (baseline+12 weeks); T3: after the second phase (baseline+24 weeks). #: administration at T0 took place to compensate for learning effects. : healthy lifestyle goals were set at T1.