This post will be about a very difficult topic: childhood abuse. Along with colleagues Dr Kari Johansson and Dr Signy Reynisdottir, I have just published a study that I hope will provide some much needed insight into a much-overlooked topic: how childhood abuse leads to an increased risk of weight gain and eventually obesity.
Having been an obesity researcher for 15 years, I have been fully aware since very early days at work that many (if not most) of our patients have had very difficult childhoods. Too many for it to be a coincidence. But for years I was very reluctant to look into this, the topic was just too much for me, too demanding, too hard. Then one day just over a year ago I decided enough was enough, I had heard one depressing story too many. I decided to follow my intuition and really have a look at the published literature to see what was out there.
I quickly came to the conclusion that there was more than enough data for a solid systematic review and meta-anaysis. I enrolled the help of some willing colleagues, and we started collecting everything that had ever been published, and then we quantified the risk of being obese as an adult in individuals who had experienced childhood abuse or not. Reading those papers and extracting the data was enough for me to go into some kind of reclusive state, it was definately a major emotional challenge.
What we found was a consistent elevation in risk of obesity in adults who had suffered childhood abuse compared to those who did not suffer abuse. Moreover, the pattern was very consistent, across all different types of abuse, such as emotional, physical and sexual, including a positive dose-response association, i.e. the more abuse, the greater the risk of obesity. These are clear signs of causality. Finally some vindication for all those who talked about this uncomfortable subject, including patients, but were pretty much ignored year after year.
The mechanisms behind why abuse leads to weight gain are multifaceted but include increased psychological and emotional distress, negative self-belief, low self-esteem, insecurity, shame and guilt, reduced metabolism (oh yes, stress substantially lowers your metabolism and lipid clearance, more on that soon), inflammation, HPA-axis dysregulation, appetite up-regulation, cognitive decline, sleep disturbances, maladaptive coping responses, and so on and on.
Modern medicine is thankfully starting to wake up to the fact that negative life experiences have markedly adverse effects on health. And yet the media and many others who should know better keep piling the guilt and shame on overweight and obese individuals by saying that they need to exercise more and eat less, when there is so much more to the story.
Hemmingsson E, Johansson K, Reynisdottir S. Effects of childhood abuse on adult obesity: a systematic review and meta-analysis. Obesity Reviews 2014, epub 14 August.