“Common wisdom” is an idea that feels comfortable and easy to accept. In our society, the belief that if you’re “overweight,” you should lose weight, is one of those ideas. “Everybody knows…”
Have you heard of the Semmelweis reflex? It’s a metaphor for the kneejerk, reflexive tendency to reject new evidence or knowledge because it contradicts existing, established beliefs or norms. In other words, because it contradicts “common wisdom.”
Allow me to briefly introduce you to Ignaz Semmelweis, before looking at how his legacy affects our societal beliefs about weight, weight loss and health.
Ignaz Semmelweis and the resistance to new medical evidence
In 1947, Hungarian physician Ignaz Semmelweis [1] discovered that deaths from “childbed fever” — bacterial infection of the female reproductive tract following childbirth or miscarriage — dropped dramatically when doctors disinfected their hands before moving from one person to another.
Sounds reasonable, right? Especially given that the doctors were moving from doing an autopsy then immediately delivering a baby. Imagine you’re a pregnant woman in labor, and your doctor comes straight from having his bare hands in a corpse and then puts those bare hands, with whatever bacteria is on them, in your business? Doctors’ maternity wards had three times the infection rates as midwives’ wards — because midwives weren’t also performing autopsies.
Despite the fact that Semmelweis published his findings, which showed that handwashing reduced deaths from childbed fever to less than 1%, his observations were rejected by the medical community. This was partly because he couldn’t offer a scientific explanation for his observations, but also because doctors were offended at the very suggestion that they should wash their hands. Some simply refused to believe that a gentleman’s hands could transmit disease.
Semmelweis was fired from the hospital, harassed by the medical community, and he eventually suffered a breakdown and died in an asylum. It wasn’t until the 1860s and 70s, when Louis Pasteur and other scientists developed the germ theory of disease, that there was finally an explanation for why hand washing mattered. Then, Dr. Semmelweis got the respect he deserved…even though he didn’t live to see it.
Belief perseverance: Why the medical community clings to BMI
The Semmelweis reflex is a kissing cousin of “belief perseverance,” the psychological tendency to cling to discredited beliefs. That’s something we certainly see today. For example, some people still believe the Earth is flat, despite abundant evidence that firmly contradicts that belief.
Another such belief is that weight loss is essential for people who have body weights above the “normal” range on the body mass index (BMI) charts. This is certainly the dominant belief in the medical and scientific communities, and in our broader culture.
Doctors are trained that they must prescribe weight loss for their larger-bodied patients, sometimes as the only “treatment” for a health issue when there are other, evidence-based, treatments available. For example, prescribing weight loss for knee pain when physical therapy is both evidence-based and more effective. Scientists doing research on the role of weight in health have trouble getting funding if their results don’t support the idea of weight loss.
Another example of this is when, in 2013, the American Medical Association decided to classify “obesity” (having a BMI of 30 or higher) as a disease requiring treatment and prevention, despite the fact that its own Council on Science and Public health concluded the year before that there wasn’t enough evidence to support this idea [2], and that calling “obesity” a disease wouldn’t help people be healthier.
The AMA argued that this classification would help increase insurance reimbursement for weight loss drugs, surgery and treatment. Follow the money.
The flaws in classifying “obesity” as a disease
The AMA, and other entities that have also classified “obesity” as a disease, also claim that this will reduce weight stigma. In other words, instead of people in larger bodies being viewed as lazy or lacking in willpower, they will simply be viewed as someone with a disease. Who is diseased.
Not only is that stigmatizing, it flies in the face of evidence that not all people with larger bodies are metabolically unhealthy, and not all people in thinner bodies are metabolically healthy. When I say “metabolically,” this loosely refers to blood pressure, cholesterol levels, blood sugar levels and chronic inflammation.
Even where there is evidence that being thin is associated with lower risks of certain health conditions, it’s a fact almost universally ignored that there is no evidence that people who are fat, and become thin, have the same lowered health risks associated with always being thin. So shrinking your body to improve your health isn’t a slam-dunk, even if you are able to keep the weight off, which most people are unable to, another inconvenient fact.
The “obesity”-as-disease rhetoric has only increased in the GLP-1 era, with weight loss getting the credit for many health effects that are directly due to the medications themselves.
And then, when someone stops taking the medication due to choice, intolerable side effects, loss of insurance coverage or other inability to pay, they’re back to square one, possibly with hunger and appetite more ravenous than anything they’ve experienced before.
How medical stubbornness fuels weight stigma and harms health
The belief that “obesity” is a disease and that recommending weight loss is the answer perseveres in the face of growing research that weight stigma may cause many of the problems that are blamed on having “too much” body fat [3].
People who experience and internalize weight stigma are more likely to:
- Suffer anxiety and depression [4]
- Avoid physical activity
- Have disordered eating behaviors (including binging, purging,
- Engage in risky weight loss attempts)
- Smoke
- Avoid preventive healthcare
- Engage in other behaviors that pose health risks
These effects of weight stigma? They’ve been observed in numerous studies across the BMI spectrum [5]. In other words, if you have a “normal” BMI and have internalized the idea that you weigh too much and your body is wrong and needs shrinking, you may experience the same effects as someone is a much larger body who is told (and believes) that their body is wrong and needs shrinking.
This is important, because part of the belief perseverance is pushback from “obesity experts” that the observed effects of weight stigma are actually due to weighing too much. They cling to the idea that body weight is a problem, even in the face of conflicting evidence.
Drilling down further, this pushback, this belief perseverance, happens in reaction to research showing that helping people adopt healthier behaviors (good nutrition [6], regular movement [7], body acceptance [8]) without trying to shrink their bodies improves health.
It also happens in reaction to research showing that people who score higher in intuitive eating traits [9] (whether they come by them naturally, or because they’ve participated in intuitive eating counseling) have fewer disordered eating behaviors, better blood pressure and cholesterol levels, more varied diets, and better psychological health.
Moving past diet culture and embracing weight-inclusive health
This continued beating of the “obesity is a disease and we have to keep promoting weight loss” drum ignores the mounting evidence that weight does not equal health, and that the pursuit of weight loss itself causes harm. Interestingly, this drumbeating became noticeably louder as the evidence against the intentional pursuit of weight loss mounted (a digging in of heels, if you will). Now, with GLP-1s, the volume is almost intolerable at times.
Why do people cling to old beliefs? Sometimes money is at stake, but also, the process of abandoning one of our convictions is a little like going through the grieving process [10]. I certainly see that with individuals who are personally working on giving up the pursuit of dieting and the “thin ideal.”
This is where self-compassion [11] is key. I say that from both personal and professional experience, as I first gave up my own pursuit of weight loss then accepted the idea that, based on the evidence, I could not ethically help my clients pursue weight loss.
Like many dietitians and healthcare providers who come to similar realizations, I went through a period of cognitive dissonance, where I simultaneously:
- Knew that the intentional pursuit of weight loss was futile and potentially harmful
- Believed that I still needed to try to help clients pursue weight loss if they desired it
This was a hard and messy process, and I am grateful that I allowed myself to experience the discomfort without becoming overwhelmed. Sort of swimming through the waves rather than letting them crash into me.
So, if you have been trying to let go of pursuing weight loss and find it difficult, you’re not alone. I hope you now understand WHY it’s so difficult, and that understanding can free some headspace to hold competing beliefs in your head as you take the next steps in your journey.
Disclaimer: All information provided here is of a general nature and is furnished only for educational purposes. This information is not to be taken as medical or other health advice pertaining to an individual’s specific health or medical condition. You agree that the use of this information is at your own risk.
Hi, I’m Carrie Dennett [12], MPH, RDN, a weight-inclusive registered dietitian, nutrition therapist and body image counselor. I offer compassionate, individualized care for adolescents adults of all ages, shapes, sizes and genders who want to heal from an eating disorder, disordered eating or chronic dieting [13], cultivate an accepting, respectful relationship with their bodies, and gain the freedom to live an authentic, meaningful life without obsessing about food.
Need 1-on-1 help for your nutrition, eating, or body image concerns? Find out how to get started [14]. I’m in-network with Regence BCBS, FirstChoice Health, Providence of Oregon Health Plan and United Healthcare, and can bill Blue Cross and/or Blue Shield insurances in many states. If I don’t take your insurance, I can help you seek reimbursement on your own. To learn more, explore my insurance and services areas page [15].