In this single case study, the author presented an in-depth description and analysis of a coaching intervention with focus on weight loss, conducted over 10 sessions in the course of 17 months. The client was a well-educated woman in her late thirties, who had tried many different forms of dieting over the years – with little and no lasting effect. In his coaching approach, the author went beyond a pure behavioural change model, i.e. based on the Health Belief Model, and tried to take a whole-life perspective, where the client learned to link specific events and habits in her work life and everyday life with specific eating habits. In their collaborative practice, coach and coachee initiated changes both in regard to diet, physical activity, and healthy life style in general. In a theoretical section, the change in understanding with regard to overeating was presented. Finally an intra-active model – viewing the client as a self-reflective individual – was used as theoretical basis. A narrative analysis of the first session and a cross-session examination was presented to show, analyse and understand the procedure of the coaching approach. Finally, the voice of the coachee was heard in regard to her personal experiences during the process. The data material was based on audio-recordings of selected sessions, notes written by the coach from every session, and final written reflections by the coachee.