Thinking about obesity: calmly, rationally and outside the box

When I was a rotating intern at Sacred Heart Medical Center, long ago, I attended rounds with the then head of medicine Dr. Patrick Tennison. Dr. Tennison was a thin, dark haired, intense guy who years later would save my life, but at that time was obsessed with imbuing young doctors with a sense of urgency about diagnostic dilemmas. He was more like a highly competitive detective than your typical doctor. “The main thing,” he told us “is to be the first to make the right diagnosis.” What he actually said was more medical-speak: “be the first to make the dx”. Make the dx. How could I disagree? Well I didn’t, of course, though I took issue with the “be the first” bit, since that seemed unnecessarily competitive to me. Who cares if you’re the first?  The important part (from the patient’s point of view) is that you make the correct diagnosis. I have thought about Dr. Tennison’s intensity around ‘making the diagnosis’ for many years.  And nowhere does it seem more important to me now than in the field of obesity. Allow me to explain. Now, in my trying to figure out how to think about the clinical dilemmas of obesity, add the fact that I went to Reed College (like Steve Jobs) and dropped out (also like him).  Why do I mention Mr. Jobs, or Reed for that matter?  Because he later became famous for (among other things!) the logo “think different”, which was taking a page from Reed’s playbook in a big way. When you have a big problem, you need to think different. And we have a big problem. That problem is obesity. If you read my blogs you have heard me say that science will save us all. Obesity is a domain in desperate need of translational science — i.e. science that goes from the “bench” or lab to the clinic or patient. The field of obesity treatment, and the deluge of articles and books written on the subject, are riddled with the confounders of personal orientation towards fat people, fat prejudice, outdated beliefs about the efficacy of dieting, the worship of exercise as a solution to all problems, a glut of research dollars available to anyone saying they are working on obesity related problems, lack of good medications, poor understanding of the basic science of human metabolism and weight homeostasis… and by a failure to think clearly about diagnosis.  So back to Tennison. In our search for a “cure” for obesity and its attendant medical problems I think we need to go back to diagnostic basics.  The most basic start would be making the right diagnosis in the first place. It seems likely to me that the word “obesity” is rather like the term “pulmonary disease”.  If you have a “pulmonary disease” this could mean you have:  A. cancer of the lung   B. asthma  C. cystic fibrosis  D. a common cold  E. tuberculosis… you get the idea.  It’s not a diagnosis, it’s a category, and it encompasses conditions that are terminal and those that are trivial.  I think that the term “obesity” is going to turn out to be like that. In my opinion, there are not only going to be grades of high body weight (e.g. overweight by some definition, obese, massively obese and obese such that it is not compatible with life even in the short term), but there are going to be different etiologies (causes) of obesity.  In other words, there will not be one kind of obesity but rather a slew of different clinical entities whose final common pathway is a higher than average—even much higher than average —body weight.  Understanding this will be critical to understanding when/if intervention is called for and what kind of intervention is likely to work. I suspect that there will be obesity caused by binge eating.  In this scenario, the condition or illness is not “obesity”, it is binge eating disorder.  Obesity would be a symptom, as cough is a symptom of lung disease. I suspect there will be leptin resistance-caused or promoted obesity. We know there are rare genetic conditions which result in obesity (Prader Willi, absence of leptin, etc.). There may be infectious obesity. There may be obesity caused by our intestinal flora. There may be diet-induced obesity, or rather, dieting induced. There may be endocrine disruptor induced metabolic disease, which results in metabolic derangements related to leptin, grehlin, MSH 3 & 4 receptors or other hormones. There is (rare) hypothyroid-induced obesity. There may be simple hyper-alimentation (overeating) induced obesity, although I suspect that such overeating will be found to have a brain-based cause, given the massive social disincentives to being fat. Another way to say it is, “obesity is not one condition, it is several”.  Or “there are many different kinds of obesity”. So, first get the diagnosis. Second, throw out the prejudice. Third, look for the science. Let’s get started.