Erik Hemmiingsson, PhD, Obesity Research Centre, Karolinska Institute, Stockholm, Sweden
Today’s guest post comes from Erik Hemmingsson, PhD, a Group Leader at the Obesity Center, Department of Medicine, Karolinska Institute, Stockholm, Sweden. His group studies the role of psychological and emotional distress in weight gain and obesity by mapping life events that influence stress, metabolism and body weight. Erik has a PhD in Exercise and Health Sciences from the University of Bristol (2004) and a PhD in Medicine from Karolinska Institutet.
I work as a researcher in a specialized obesity treatment center at a university hospital in Sweden. My job is to develop new and more effective treatment and prevention methods so that we can hopefully confine obesity to the history books some day.
For many years I mostly did studies on behaviour therapy combined with low energy diets. Since this did not result in any major breakthroughs, I decided to try something a little different.
I had been aware of that many of our patients had experienced difficult childhoods. There were so many sad stories, but I didn’t fancy doing any research on the topic, it was too painful. But then my attitude gradually started to change about a year ago. It was clear that our current treatment methods were woefully ineffective, but I also became more receptive to all those troublesome stories from the patients. Enough was enough, it was time act. So, like Neo in the Matrix movies, I decided to take the red pill, and delve deeper into the very uncomfortable subject of childhood abuse and adult obesity.
I searched the literature and quickly saw that there were more than enough studies for a systematic review and meta-analysis. I enlisted the help of Dr Kari Johansson and Dr Signy Reynisdottir, and got to work.
What we found very much confirmed all those clinical observations, i.e. there was a very robust association between childhood abuse and adult obesity. The association was also very consistent across difference types of abuse, with an increased risk of about 30-40%. There was also a dose-response association, i.e. the more abuse, the greater the risk of obesity.
While this study confirmed something very important, it was also clear that not everyone who suffers childhood abuse develops obesity, or that all obese individuals have suffered childhood abuse, or the effects would have been even more pronounced. But for me, the study proved that stressful childhood experiences can easily manifest as obesity many years later. This led me even deeper down the rabbit hole. I wanted to know why.
I decided to try and piece together different ideas about how obesity develops in relation to stressful life events. This resulted in a new conceptual causal model consisting of six different developmental stages. Like many diseases, obesity development is more likely when there is socioeconomic disadvantage (applies mainly to Europe and North America). Socioeconomic disadvantage can very easily trigger a chain of events that include adult distress, a disharmonious family environment, offspring distress, psychological and emotional overload, and finally disruption of homeostasis through such mechanisms as maladaptive coping responses, stress, mental health problems, reduced metabolism, appetite up-regulation and inflammation.
Much more research is needed to validate the model, but if there is some truth to this theory, which the childhood abuse meta-analysis clearly suggests that there is, then my hope is that we can use this information to develop more effective treatment and prevention methods.
My other hope is that some of the truly horrendous stigma, shame and discrimination that the obese experience can gradually be alleviated, since there is clearly a lot more to obesity etiology than the commonly held preconception that obese individuals are merely lazy and overindulgent.
After having done all this work on obesity etiology, I would say that my top-3 reasons we have an obesity epidemic (in no particular order) are socioeconomic inequality, the junk food invasion, and psychological and emotional distress patterns (usually established at an early age). And when you combine all three you have the perfect storm for weight gain.
You can find more information at my blog at www.holisticobesity.com
Hemmingsson E, Johansson K, Reynisdottir S. Effects of childhood abuse on adult obesity: a systematic review and meta-analysis. Obesity Reviews (epub 15 August 2014).
Hemmingsson E. A new model of the role of psychological and emotional distress in promoting obesity: conceptual review with implications for treatment and prevention. Obesity Reviews 2014, 15:769-779.