Anyone who has ever seriously looked at the genetics of obesity should be well aware that body weight and size is a highly heritable trait.
As one may expect, this heritability extends across the entire spectrum of body size. Thus, if there are genes that explain obesity, then perhaps certain variations of these very same genes may do the exact opposite – i.e. promote “skinniness”.
In fact, we all know these people, who appear to be highly weight-gain “resistant”, in that they can apparently eat all day without gaining a gram of body fat or simply find it very difficult to “overeat” even when surrounded by highly-palatable food.
Now, a study by Fernando Riveros-McKay and colleagues, published in PLOS Genetics, compares the genetics of thinness with that of severe obesity.
Using genome-wide association studies, the researchers not only show that the heritability of thinness was comparable to that of severe obesity but they also confirmed the existence of 10 genetic loci that had been previously associated with obesity (as well as an addition obesity and BMI-associated locus (PKHD1).
As there may well be non-genetic reasons for people to fall into the “thin” end of the size spectrum, the researchers were careful to only include individuals who appeared in good health and especially excluded individuals with anorexia.
Overall, these finding are consistent with animal studies that have also identified loci/genes associated with thinness/decreased body weight due to reduced food intake/increased energy expenditure/resistance to high fat diet-induced obesity, mechanisms that the authors hypothesise may also contribute to human thinness.
Clearly, further genetic and phenotypic studies focused on persistently thin individuals may provide new insights into the mechanisms regulating human energy balance and may uncover potential anti-obesity drug targets.
While I am currently teaching at a Harvard Medical School course on obesity for obesity educators here in Las Vegas, I thought it may be appropriate to post a link to my recent Obesity Canada webinar (about 60 mins) on why obesity is a chronic disease.
The full video can be accessed by clicking here
Las Vegas, NV
If there is one thing for sure, when it comes to managing obesity, one size does not fit all. In the same manner as there are hundreds of paths that lead to obesity, predicting the treatment that works best for any given patient is almost impossible – what works for one, may do nothing for another (treatments fail patients, patients never fail treatments).
Thus, in our analysis of interviews with patients and providers, published in Clinical Obesity, the eighth theme that emerged, was the importance of experimenting and reevaluating.
“Participants experimented with different actions, arranged appointments with interdisciplinary providers, or tried out community resources. Some changed their action plan and implemented different behaviours inspired through the consultation. During follow-up interviews, people reflected on what worked, what did not and what needed adjusting. Participants found that having someone ask how things are going was helpful for accountability and motivation. These conversations also helped them develop solutions for barriers.
It became glaringly obvious that, as with any other chronic disease, obesity care needs creating a supportive long-term relationship in order to respond to emerging barriers, shifting experiences, illness and treatment burden – what works great at one point may stop working when situations change. Things that seem impossible at first may well become possible over time.
If there is one thing that I have learnt in my dealing with patients, it is modesty in professing to have the solution for every problem.
As I have said, people who think there is a simple answer to every question, generally don’t even understand the question.
As should be clear by now, obesity management often involves reframing the story, changing misconceptions about obesity, managing expectations, reorienting from weight to health goals.
All of this requires reflection both on part of the patient and the provider.
Thus, fostering reflection was one of the key themes that emerged from out interviews with patients and providers published in Clinical Obesity.
“For many participants, the insights and shifts in beliefs about self and health required time to reflect and integrate.People processed new understandings in different ways and internalized them to different degrees.”
While some patients went though this process of reflection in conversations with family, friends or their clinician, many reported that keeping a journal of their progress was a key instrument:
I routinely tell my patients to write down key events, emotional issues, stressors, milestones, challenges, and successes in their journals (not just their food intake and physical activity). Many have told me how helpful they find this and how much they have discovered about themselves through this exercise.
Although many of the comorbidities associated with obesity are directly linked to excess body weight, and losing weight has been shown to dramatically improve overall health and well-being (at least in people living with obesity), it is always important to remember that the ultimate goal of obesity management is to improve health and not just move numbers on the scale.
In this context, it is important to help patients identify and focus on health rather than on weight goals – indeed, patients tend to do best when they focus goals that are important to them – independent of what may or may not happen to their weight.
Thus, in our recent analysis of patient and provider interviews, published in Clinical Obesity, we found that both patients and providers agree on the importance of orienting all actions on goals valued by the patient.
“Context integration and priority setting led into thinking about what actions, strategies and resources may be of interest for the patient. Providers and patients identified a functional or value goal that served as an overarching orientation for action planning. A majority of participants wanted to plan actions, some chose to first reflect on thenew understandings gained from the conversation. Possible actions emerged from the conversation and differed widely between patients. They included addressing mental health, pain, sleep, seeking financial and social supports, considering anti-obesity medication or bariatric surgery.”
This is where it is always important to remind ourselves that losing weight cannot be a behavioural goal, as it is not a behaviour (losing weight is something your body may or may not do in response to a behaviour – you can control your behaviour but not how your body responds to this behaviour). Also, healthy behaviours will always improve your health, irrespective of whether or not you lose weight.
“While helping with accountability and motivation, action planning was described as less decisive than the cognitive and emotional work that led to context integration and priorities. However, this perception shifted over time, andmany participants later reflected on the benefits of planning specific and achievable actions for outcomes.”
Again, obesity management is best done in a long-term therapeutic partnership (as with any other chronic disease), and reorienting patients away from weight to non-wieght goals is a process that takes time but reaps significant rewards.