Source: Run Stop Shop
As some of you know, I work in health and medical research, and more specifically, in mental health research. If you work in mental health research, you learn early on that good research takes weight status / Body Mass Index into account, because it is so strongly associated with depression in particular and mental health difficulties in general - at least in females. This relationship is generally accepted as being bi-directional: mental health problems are likely to predict overweight/obesity just as much as overweight/obesity predict mental health problems (see this study and this study for examples).
There are a few things we know about overweight and obesity. It's increasing in prevalence, obviously. It's increasing particularly dramatically in childhood and adolescence. It's associated with a whole range of physical health problems (as the above shows, cardiovascular disease and Type 2 Diabetes in particular) as well as mental health problems, social problems, disordered eating (particularly binge eating), and distress about weight. Again, these effects are more pronounced for females than for males.
We also know that not everyone who is overweight or obese has these difficulties. Weight, like so many other things, is meant to normally distributed. Remember the bell shaped curve you learnt about in maths? There will always be some people who are classified as "overweight", just as there will always be some people who are classified as "underweight". We aren't all the same height. We don't all have the same shoe size. Variation is normal. Being overweight isn't always bad, or a result of overeating, or a sign of medical problems. In older men, being slightly overweight actually seems to be protective. It gives people more reserves in case of infection or illness - it may be healthier than being a "healthy weight"! In other age groups and in women, the health consequences linked to overweight and obesity seem to be linked, mostly, to obesity. We lump overweight and obesity together but they have quite different consequences for our health.
There is also a lot we don't know. The main thing is how to fix the problem. Dieting does not generally work, and in many cases will make things worse. Psychological treatments are better than commercial diets, but still quite ineffective in the long term. We are now at the point where national guidelines in Australia recommend weight loss surgery (bariatric surgery) as a serious treatment consideration for postpubertal adolescents and adults with obesity.
What about prevention? Surely that is the best place to start? Well, yes. Of course. But how? There is some great research on environmental contributors to overweight/obesity, and we know that environments where walking and cycling are easier, playgrounds are more available for children, fast food outlets are not scattered at regular distances, and fresh nutritious food is readily available are all positive. We also know they're not likely to be enough.
The truth is, weight is a complicated thing. It is influenced by genetics. We are, to a certain extent, evolutionarily designed to eat when food is available and store fat in case it becomes scarce in the future. We have created so many labour saving devices, modes of easy transport, and foods of immense calorie density that we have surprised our bodies and left them unprepared for this latest evolutionary challenge of too much, not too little (although outside of Western societies of course things are still reversed). Many of us have lost the skill of eating to genuine physical hunger, as opposed to the many other reasons that can prompt us to eat today. You are also more likely to be overweight or obese if you live in a socially disadvantaged area. It's social, too.
I don't have the answers, and writing this post is not about giving them to you. I did, however, have even more cause to think about these issues this week because I recently finished reading The Heavy: A mother, a daughter, a diet by Dara-Lynn Weiss. Some of you may remember her as the author of the highly controversial article published in Vogue in 2012, when she wrote about placing her 7-year-old obese daughter on a strict calorie controlled diet. The public backlash was huge. The book explains things in more detail.
Professionally and personally, I don't promote dieting. I actively discourage it. Dieting in teenagers predicts weight gain not loss. It is the most reliable predictor of binge eating and other eating disorder symptoms. I think eating according to the healthy eating guidelines is a good stance to take. I am fond of moderation, balance and staying away from extremes. I wish we could all focus a bit less on weight. I like studies showing that regardless of weight status, good nutrition and physical activity are associated with positive health outcomes.
And yet, Dara-Lynn relayed how focusing on general healthy eating didn't really work in their case. Her daughter, like many others out there, did not seem to have an 'off' switch when it came to food. Reducing her energy intake to a level that would halt weight gain and reverse obesity was tough, and restrictive. It did, over a year, work - in the short term at least, her daughter is now a healthy weight and functioning well. We could argue over the different ways it could be done, but clearly some parents are faced with a tough situation in helping their children eat appropriate amounts for their energy needs. Other parents face the opposite dilemma - children who could benefit from eating more, but don't show interest in doing so.
Again, I don't have the answers. My message is usually that healthy eating and regular exercise are what we need to focus on, in a balanced and non-extreme way: the kind of way that includes lots of fruit and vegetables, but also chocolate and cake on birthdays. A way that involves real rather than 'diet' food. I take the stance that weight will then take care of itself. Some of us will be an average size, some thinner, some larger. Clearly, though, it isn't as simple as that for many people out there. The above diagram highlights that. So what do we do?
I'd love to hear your thoughts.
Some references, for those of you who care about such things:
- Australian National Health and Medical Research Council guidelines, 2013. Clinical Practice Guidelines for the management of overweight and obesity in adults, adolescents and children in Australia. Available in full for free at http://www.nhmrc.gov.au/guidelines/publications/n57 .
- Auyeung et al., 2010. Survival in older men may benefit from being slightly overweight and centrally obese - A 5-year follow-up study in 4000 older adults using DXA. The Journals of Gerontology. Available in full for free at http://biomedgerontology.oxfordjournals.org/content/65A/1/99.short .
- Blaine, 2008. Does obesity cause depression? A meta-analysis of longitudinal studies of depression and weight control. Journal of Health Psychology. Available in full for free at http://hpq.sagepub.com/content/13/8/1190.short .
- Frisco et al., 2013. Weight change and depression among US young women during the transition to adulthood. American Journal of Epidemiology. Available as an abstract only at http://aje.oxfordjournals.org/content/early/2013/06/07/aje.kws462.full .
- Hasler et al., 2004. The association between psychopathology and being overweight: A 20-year prospective study. Psychological Medicine. Available as an abstract only at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=242047 .
- Mokdad et al., 2003. Prevalence of obesity, diabetes and obesity-related health risk factors. The Journal of the American Medical Association. Available in full for free at http://jama.jamanetwork.com/article.aspx?articleid=195663 .
- Penedo & Dahn, 2005. Exercise and well-being: A review of mental and physical health benefits associated with physical activity. Current Opinion in Psychiatry. Available as an abstract only at http://journals.lww.com/co-psychiatry/Abstract/2005/03000/Exercise_and_well_being__a_review_of_mental_and.13.aspx .
- Schwimmer et al., 2003. Health-related quality of life of severely obese children and adolescents. The Journal of the American Medical Association. Available in full for free at http://jama.jamanetwork.com/article.aspx?articleid=196343 .