Discussion
In a sample of 70 patients in a Norwegian regional centre for morbid obesity, we divided the adverse and stressful life experiences reported by these patients into twelve categories. More than one-half of the patients had experiences that fitted into three or more of these categories. The most frequent were serious relationship ruptures, significant insecurity in childhood and a feeling of lack of care by parents. These were followed by a series of more specifically defined experiences, such as sexual abuse or having witnessed violence. As illustrated by Figure 1 and Table 1, the data material includes a number of complex life stories that describe series of stressful and interwoven experiences, summarised in keywords. The experience of relationship ruptures, violence and insecurity in early life not infrequently recurs in new constellations in the patients' adult life.
The study design was chosen because we wanted to explore a topic that international research highlights as important, but of which there is little knowledge in a Norwegian context (16). The participant group was heterogenous in terms of age, marital status, education and employment status, which indicates that the findings may have transfer value to similar patient groups. The proportion of women (81 %) was somewhat higher than the proportion in the Regional Centre for Morbid Obesity in Bodø where the study was conducted (70 %). It is difficult to ascertain whether the participants were significantly different in other respects from those who did not respond to the invitation.
The objective of the study was not to obtain generally valid prevalence data or draw any direct conclusions with regard to causal links between trauma and obesity. However, the study provides insight into what a sample of 70 patients with morbid obesity chose to reveal to an experienced doctor who provided space for a dialogue on adverse life experiences. The results should be seen in light of the fact that underreporting of trauma and abuse appears to be common, in clinical practice as well as in research (16, 17). The participants themselves considered these experiences as relevant in the clinical situation in question, and they contributed actively to their documentation.
During the analysis we were aware of our preconceptions and sought to the best of our ability to avoid prejudiced interpretations. We recognised that important nuances in the individual narratives could easily be lost or misinterpreted. Many narratives indicated complex experiences that could be subsumed under more than one category. The experiences were as far as possible categorised in direct consistency with the discharge summary. For example, information on the loss of a parent (category 8) was not categorised also as a feeling of insecurity in childhood (category 1), unless this had been explicitly described.
The analysis aimed to identify different categories of stressful life experiences that were clinically relevant. Such an analytical process can be driven by existing theory and evidence, and contribute to the development of new theories (14). The analysis was influenced by the group of authors' general knowledge of and research on correlations between life experiences and illness (6), (18–19).
Many of the categories (numbered 2, 4–9 and 12 in Box 2) could immediately be related to three key international studies (5, 20, 21). Moreover, the material provided the basis for defining some further categories (numbered 1, 3, 10 and 11), which could also be related to relevant documentation (see examples below). International literature in this area includes clinical research, basic research and epidemiological studies (12, 16). A number of publications document general associations between adverse experiences on the one hand and emotionally driven eating patterns and development of obesity on the other (4). There is a rapidly growing insight into the physiology that links stress to metabolic syndrome, appetite regulation and obesity (22). Furthermore, some epidemiological studies show associations between obesity and one or more trauma categories (referred to in 12).
A persistent mental 'state of alarm' seems to be a common denominator for many of the categories of experiences. Categories 1 and 2 point towards a fundamental lack of existential security early in life. The biological 'costs' of such a state of alarm feature prominently in modern stress research, including the allostatic load model. It describes the links between long-term stress, physiological dysregulation and development of disease, including obesity (23, 24). A feeling of insecurity and uncertainty is a key feature also in Hemmingson's obesity model (4). The ACE study showed a dose-response relationship between traumatic life experiences and morbid obesity (5). Later studies have confirmed these associations for sexual abuse, other forms of violence, emotional maltreatment or neglect, and substance abuse in the home (3, 7, 9). Relationship ruptures in the form of early loss of a parent increase the risk of development of obesity, irrespective of other stressful life events (25, 26). Bullying and obesity are mutually related (27, 28). Persistent, stressful care responsibilities are associated with physiological load, and an association with obesity is therefore plausible (29).
Our material includes several examples of poor dental health and odontophobia. Childhood adversity is associated with chronic systemic inflammation, which may interact with a poor diet and poor dental hygiene (30). Experience of violence and abuse predispose for odontophobia (31). Stressful childhood experiences may thus increase the risk of poor dental and oral health by way of a number of different mechanisms (30, 31).
An important finding in this study is that many participants reported multiple types of stressful life experiences and thus illustrated the relevance of the term 'complex traumas', not least with regard to the conditions of vulnerable children's upbringing (32). Another prominent finding was that participants who had experienced violence or abuse in childhood were also exposed to new incidents in adult life – so-called re-victimisation (33).
We hope that the study can motivate clinicians to be open and attentive in their encounters with severely obese patients. Addressing negative life experiences and trauma in relevant clinical settings does not lead to re-traumatisation (16, 17). A trauma-sensitive medical history that does not immediately seek to elicit certain types of information can provide space for consequential information without appearing as intrusive (34), and can help provide deeper and more adequate insight into the complexity that underlies an obesity problem. Such insight can reinforce the patient's self-insight and self-esteem and reduce the stigma and shame associated with obesity. This is health-promoting in itself (11, 35, 36). Current standardised patient pathways do little to facilitate broad, trauma-sensitive assessment and treatment of morbid obesity and the complex health problems associated with this diagnosis. Achieving a professional consensus about suitable new working methods is a considerable challenge. An integrated approach requires not only a well-functioning logistical collaboration across the current boundaries between somatic and mental health services; it also requires an updated and non-dualistic understanding of body and disease (19).