Let’s shed some obesity myths!

There are a lot of myths and misconceptions surrounding obesity… And then there are also reactive opposite myths and misconceptions, which can sometimes be just as harmful!

To tackle them all would take a book, but in classic 10almonds style, we’re going to put a spotlight on some of the ones that might make the biggest difference:

True or False: Obesity is genetically pre-determined

False… With caveats.

Some interesting results have been found from twin studies and adoption studies, showing that genes definitely play some role, but lifestyle is—for most people—the biggest factor:

• The body-mass index of twins who have been reared apart
• An adoption study of human obesity
• Using a sibling-adoption design to parse genetic and environmental influences on children’s body mass index

In short: genes predispose; they don’t predetermine. But that predisposition alone can make quite a big difference, if it in turn leads to different lifestyle factors.

But upon seeing those papers centering BMI, let’s consider…

True or False: BMI is a good, accurate measure of health in the context of bodyweight

False… Unless you’re a very large group of thin white men of moderate height, which was the demographic the system was built around.

Bonus information: it was never intended to be used to measure the weight-related health of any individual (not even an individual thin white man of moderate height), but rather, as a tool to look at large-scale demographic trends.

Basically, as a system, it’s being used in a way it was never made for, and the results of that misappropriation of an epidemiological tool for individual health are predictably unhelpful.

To do a deep-dive into all the flaws of the BMI system, which are many, we’d need to devote a whole main feature just to that.

Update: we have now done so!

Here it is: When BMI Doesn’t Measure Up

True or False: Obesity does not meaningfully impact more general health

False… In more ways than one (but there are caveats)

Obesity is highly correlated with increased risk of all-cause mortality, and weight loss, correspondingly, correlates with a reduced risk. See for example:

Effects of weight loss interventions for adults who are obese on mortality, cardiovascular disease, and cancer: systematic review and meta-analysis

So what are the caveats?

Let’s put it this way: owning a horse is highly correlated with increased healthy longevity. And while owning a horse may come with some exercise and relaxation (both of which are good for the health), it’s probably mostly not the horse itself that conveys the health benefits… it’s that someone who has the resources to look after a horse, probably has the resources to look after their own health too.

So sometimes there can be a reason for a correlation (it’s not a coincidence!) but the causative factor is partially (or in some cases, entirely) something else.

So how could this play out with obesity?

There’s a lot of discrimination in healthcare settings, unfortunately! In this case, it often happens that a thin person goes in with a medical problem and gets treated for that, while a fat person can go in with the same medical problem and be told “you should try losing some weight”.

Top tip if this happens to you… Ask: “what would you advise/prescribe to a thin person with my same symptoms?”

Other things may be more systemic, for example:

When a thin person goes to get their blood pressure taken, and that goes smoothly, while a fat person goes to get their blood pressure taken, and there’s not a blood pressure cuff to fit them, is the problem the size of the person or the size of the cuff? It all depends on perspective, in a world built around thin people.

That’s a trivial-seeming example, but the same principle has far-reaching (and harmful) implications in healthcare in general, e.g:

• Surgeons being untrained (and/or unwilling) to operate on fat people
• Getting a one-size-fits-all dose that was calculated using average weight, and now doesn’t work
• MRI machines are famously claustrophobia-inducing for thin people; now try not fitting in it in the first place

…and so forth. So oftentimes, obesity will be correlated with a poor healthcare outcome, where the problem is not actually the obesity itself, but rather the system having been set up with thin people in mind.

It would be like saying “Having O- blood type results in higher risks when receiving blood transfusions”, while omitting to add “…because we didn’t stock O- blood”.

True or False: to reduce obesity, just eat less and move more!

False… Mostly.

Moving more is almost always good for most people. When it comes to diet, quality is much more important than quantity. But these factors alone are only part of the picture!

But beyond diet and exercise, there are many other implicated factors in weight gain, weight maintenance, and weight loss, including but not limited to:

• Disrupted sleep
• Chronic stress
• Chronic pain
• Hormonal imbalances
• Physical disabilities that preclude a lot of exercise
• Mental health issues that add (and compound) extra levels of challenge
• Medications that throw all kinds of spanners into the works with their side effects

…and even just those first two things, diet and exercise, are not always so correlated to weight as one might think—studies have found that the difference for exercise especially is often marginal:

Read: Widespread misconceptions about obesity ← academic article in the Journal of the College of Family Physicians of Canada