All patients of one organisation (GGZ Friesland) are invited to wear a pedometer (Yamax SW200 ) for at least seven days, reporting the total steps per day in a diary. A trained research assistant measures patients’ body fat percentage in standing position  by bioelectrical impedance analysis (BIA) in triplicate using a single-frequency bioimpedance analyzer (Model BIA 101, AKERN Srl, Italy) [46, 47]. In order to calculate the body fat percentage using a formula, height and weight are measured in accordance with previously described methods.