Let’s start this conversation with a prompt…
“Please name a disease that only people in larger bodies get.”
I’ll wait...let me guess you’ve got nothing? There is not a single disease that only people in larger bodies get, and yet we often hear that high/ “excess” weight causes disease.
In this series, I hope to help break down the science behind the “Obesity” epidemic and begin to change the way we view health. As always, it’s important to recognize that having health, and pursuing health do not have moral value, and shouldn’t be a prerequisite for someone to be respected. Additionally, the pursuit of health requires privilege and isn’t accessible to all (a post on that to come soon).
Let’s start with the biggest myth: Long-term weight-loss is possible through diet and exercise, with the underlying assumption that it will improve health.
→ Science shows that for around 95% of the population, weight-loss cannot be maintained for longer than five years (Mann et al.).
The recommendations from doctors, friends, family, and your aunt’s dog that have said, “You just need to eat a little less and move a little more to lose weight,” is rooted in faulty science and weight bias.
Our bodies have a “set-point” which is a weight range that will allow our body to function at its best (Harrison). Our body will fight to maintain this weight range if we begin to drop out of it. Our body’s physiology doesn’t recognize that we are in the 21st century, and it is still wired to protect us from harm that could have killed us centuries ago. When we restrict our caloric intake whether it be due to food insecurity, restriction from a diet, or any other reason-- our body views this as famine. To keep us alive, it wants to return us to the set-point range slowing the body’s metabolism, reducing fullness hormones (leptin), increasing hunger hormones (ghrelin) and increasing the value of food-encouraging you to eat more energy-dense foods (Harrison). These biological changes are why intentional weight-loss will not work for the majority of people.
In addition to returning our body to its set-point range, our brain wants to ensure that we have extra energy stored, in case another “famine” returns. The body then increases the set-point range, making it a little higher. (Let’s take a moment and appreciate how incredibly wise our body is, with the mechanisms that it is capable of utilizing to keep us alive.) This higher range is why two-thirds of dieters end up gaining back more weight after their diet (Harrison). When someone continues to fight this biological response by again restricting energy availability, the body continues to view the changes as famine, resulting in what is known as weight cycling.
Weight-cycling is the weight fluctuations that occur from losing weight, only to have the body return to the set-point (and increase it a little to protect the body for future “famines”).
Here’s the thing, weight-cycling changes your metabolic profile, and this is a risk factor for various health conditions, including all-cause mortality, diabetes morbidity, and heart disease (O’Hara and Taylor). Interestingly enough...these conditions have all been blamed on weight. Still, research shows that a stable weight (even stable higher weight) doesn’t increase the risk for all-cause mortality, BUT weight fluctuations (weight cycling) does result in the increased risk (Campos et al.). This leads to the paradox of recommending weight-loss because it often results in weight-cycling, the healthcare profession is actually increasing the risk for a variety of diseases.
I am guessing your next question is something along the lines of, “What about all the research that shows that weight-loss improves (fill in the blank health condition)?”
I do not deny that there is a ton of research on “Obesity” and chronic diseases, worse health outcomes, etc. However, there is not a lot of quality research on the impacts of “Obesity” and chronic disease, health outcomes, etc.
For starters, we have no research showing a causal relationship between weight and health, only correlational. Another example of a correlational relationship is seen with the increase of ice cream sales mirroring the increase of drownings. However, we don’t make statements like “Don’t buy ice cream to prevent drownings!” because there are some obvious confounding variables (like summer).
Here are a few key things to consider when looking at research about weight and morbidity/mortality:
Do they control for weight-cycling? If not, the study isn’t a good predictor of health outcomes, because weight-cycling has been found to increase risk for the same diseases. Some studies have shown that all increased risk associated with high weight is gone when controlled for weight-cycling (Campos et al.).
How long is the follow-up? If they don’t follow-up past the 2-year mark, it is pretty hard to tell if the participants were able to keep the weight-loss off.
Do they control for weight stigma and other forms of oppression two independent risk factors for many diseases?
What other co-founding variables could be present that is resulting in improved outcomes (*cough cough health behaviors*)
That brings me to the grand finale (of this post anyway):
The variable that may lead to the improved outcomes in many studies might not be weight loss, rather the health behaviors the participants engage in during this time.
Research has shown that changing health behaviors will improve health outcomes, regardless of weight-loss, (in a few of these studies participants ended up gaining weight and still saw improvements!) (Campos et al.).
TLDR: Long term weight-loss isn’t sustainable for 95% of the population (Mann et. al). When we attempt weight-loss, our body will fight to maintain/return to its set-point range. This leads to weight cycling--which does increase the risk of a variety of adverse health outcomes.
Campos, Paul et al. "The Epidemiology of Overweight and Obesity: Public Health Crisis or Moral Panic?" International Journal of Epidemiology, vol. 35, no. 1, 2005, pp. 55-60, doi:10.1093/ije/dyi254.
Harrison, Christy. Anti-Diet, Little, Brown Spark, 2019.
Mann, T. et al. "Medicare's Search for Effective Obesity Treatments: Diets Are Not the Answer." Am Psychol, vol. 62, no. 3, 2007, pp. 220-233, doi:10.1037/0003-066x.62.3.220.
O’Hara, Lily and Jane Taylor. "What’s Wrong with the ‘War on Obesity?’ a Narrative Review of the Weight-Centered Health Paradigm and Development of the 3c Framework to Build Critical Competency for a Paradigm Shift." SAGE Open, vol. 8, no. 2, 2018, p. 2158244018772888, doi:10.1177/2158244018772888.