weight loss diet The “obesity crisis” is a hot topic in medicine at the moment. It is an interesting yet complicated subject—the words “obesity” or “overweight” imply a medical problem associated simply with one’s body weight and height. When considering this, we need to be aware of our internalized size stigma (as discussed in the first article in this two part series) and keep an open mind. Dieting for weight loss will not necessarily improve people’s health. In addition to this, there is no successful long-term intervention available for doctors to recommend, we know that dieting is intimately linked to eating disorders, and failure at “weight control” is highly stigmatised in both healthcare and society.
Bodyweight is determined by a complex interplay of genetic, metabolic, environmental, and behavioural factors (Mechanick, 2017; Garvey, 2020). Our set weight is essentially written into our genetics, and there are many other things that influence the size of people’s bodies that also influence their health. Societal problems like poverty, racism, and sexism could contribute to body size and shape whilst simultaneously contributing to adverse health outcomes. As with so many other areas in medicine, correlation does not imply causation and we need to recognise that weight reduction is not guaranteed to improve health or wellbeing. Advising people to diet could, however, lead to a dangerous binge-restrict cycle and send them down a path towards disordered eating.
Doctors generally believe that in order to lose weight, people just need to eat less and move more. The problem with this classic medical perspective is that it does not work. It shames patients who have been told, not only by doctors but also by society, that if they have a larger body there is something dangerous and shamefully wrong with them.
We must honour body diversity and stop focusing on weight. The theory that weight is all about calories in versus calories out, and that if people have the willpower to avoid junk food and exercise they will stop “burdening the health system with obesity” is simplistic, outdated, and judgemental, and ignores all the inequalities of society and confounding factors that contribute to health outcomes. We have seen time and time again that simply cutting calories and increasing exercise is not a sustainable way to lose weight, and that most people who do initially “succeed” ultimately regain any weight lost, or more. Yet as doctors, we continue to recommend diet and exercise to our patients. The advice we persistently give is unhelpful and dangerous.
Evidence suggests that although dieting may work for a short time, bodies quickly adapt to energy deficit. Metabolism is highly dynamic, and lowering calories activates a strong biological compensatory mechanism through initiating a cascade of metabolic and neurohormonal adaptations (Mebel, 2012; Bliss, 2018). In response to negative energy balance, levels of leptin, a satiety hormone, decrease, and levels of ghrelin, a hunger hormone, increase (Greenway, 2015; Maclean, 2011).
A further fundamental physiological adaptation is a reduction in energy expenditure (Greenway, 2015; Maclean, 2011)—partly because less energy is needed to “run” a smaller body (Leibel, 1995), and partly because metabolism becomes more efficient and effectively slows down (Camps, 2013; DeLany, 2014). All of this means that an individual, who is hungrier than before embarking on a restrictive diet, must consume even fewer calories to continue losing or even to maintain weight. And importantly, in vulnerable individuals with a genetic predisposition, energy deficit may be sufficient to trigger an eating disorder (Watson, 2019).
Enjoying cake and tea.
Source: Andreas Photiou, used with permission.
We need to shift the focus away from weight and stop stigmatising and judging people who have larger bodies. Doctors can improve people’s health and wellbeing by helping them change their behaviour—through stopping smoking, improving diet, increasing physical activity and reducing alcohol consumption. Studies have shown that people can be healthy at most weights if they engage in healthy behaviours (Loef, 2012). Mortality rates for physically fit people do not differ according to weight when subdivided into categories of “normal,” “overweight,” or “obese” (Gaesser, 2015). Habits such as eating five or more servings of fruits and vegetables per day, limiting alcohol, not smoking, and exercising moderately minimise weight-based differences in mortality (Matheson, 2012). We should teach children to trust and respect their bodies, and show them how to engage in activities that promote health and happiness—we must never restrict their food for weight loss or comment on their size or shape.
Doctors must take a holistic approach to health and encourage people to nourish themselves well and consistently, move away from a restrictive and punitive mindset, and move their bodies in a way they enjoy. The weight at which the body stabilizes when doing this may not be an “ideal” weight on the BMI scale—but that doesn’t matter. And of course, not everyone at every size is healthy—but, as Dr. Gaudiani, an eating disorder expert and physician, states, “We have to unhook an assumption of ‘health equalling thinness.'”
I personally have been at my unhealthiest—both physically and mentally—when my body was at its smallest, despite receiving endless compliments for looking “fit” and “athletic.” We must disrupt stereotypes of personal failure or success attached to body composition and redefine success as healthy behaviour change regardless of weight, body size or shape (Sharma, 2007).
As a profession, we have a long way to go. When I asked my GP husband to read an earlier draft of this article, his response was, “Well, I get what you’re trying to say—but what should I tell people to do to lose weight if telling them to make better food choices and be more active doesn’t work?” This entirely misses the point. This is exactly what we should be encouraging people to do—but with an aim to improve their health, not to reach a number on the scale. We need to take the focus off weight completely and stop talking about body size as an outcome measure.
We must also be aware that weight bias, stigma, and discrimination contribute to increased morbidity and mortality independent of weight or BMI (Sutin 2015). The cultural narrative fuels assumptions about lack of willpower and personal irresponsibility and negatively impacts the quality of healthcare we provide (Kirk, 2014). People turn negative stereotypes inwards and engage in self-blame, believing the widespread assumption that their high BMI is simply the outcome of a personal failure to take responsibility for their weight. All of this can contribute to depression, anxiety, poor self-esteem, and eating disorders, and can have a further unintended outcome of leading people to overeat and avoid physical activity.
We have a responsibility as a profession to address this and stop causing harm to our patients, but before we can do this, doctors must recognise our own biases (Lee, 2014). Self-assessment tools, such as the Implicit Association Test, provide interesting insight into our subconscious beliefs (Project Implicit, 2011). I would encourage anyone who is interested to explore this further—you may be surprised by what you discover about yourself.
Implicit weight bias in the medicine is harmful—to healthcare professionals, to our patients, and to society as a whole. We must uncouple body size from an assumption of health, illness, and morality, recognise the damage we are causing, and change the conversation from shame to helpful compassion. In this way, we can create a healthcare system and a world in which body diversity is respected, in which eating and movement are joyful, and in which all people are valued—irrespective of the size of their bodies.
I would like to thank Dr Jennifer Gaudiani, M.D., for her insightful contributions to this article.
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