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Since it’s April Fool’s Day, it’s a particularly relevant time to call out myths and misinformation about the relationship between weight and health. It is a big topic, so this is just one small piece.


April Food Day On 1st Day Of Month by KeeratiEverybody “knows” that being overweight is terrible. It’s bad for your health. It’s bad for your self-esteem. It’s bad for your mental health. Right?

But what if none of that is necessarily true? In fact, the link between increased weight and poor health is less documented than you’d think. (The relationship is more documented with morbid obesity, but less so with the categories of “obese” and “overweight.”)

The biggest error that results in linking weight and health risks is mistaking correlation for causation. Just because more health problems are found in people of increased weight, it doesn’t mean that weight is the cause. When the link between weight and health is not taken at face value, the causal relationship is not as defined.

For example, despite the common belief that increased weight is a health risk for diabetes, it is possible that weight gain is actually an early symptom of diabetes, rather than a cause.

To take an analogy: men who are bald have an increased risk for cardiovascular disease. So the answer is to give hair transplants to all bald men (after we publicly shame them for not keeping their hair). Right?

Of course, that analogy points out the fallacy that when two things are linked, it’s not the same as one thing causing the other. It’s much more likely that there’s an underlying factor. For the bald men, it is testosterone levels that underlie both hair patterns and cardiovascular disease risk.

For fat people, it is more complicated. For sure, poor nutrition and low exercise raise health risks, and can influence weight gain. However, your weight is not solely the result of your lifestyle. Genetics, gut flora, viruses, and decreased metabolism from weight cycling (“yo-yo dieting”), among other factors, influence your weight.

If you take the assumption that fat/weight causes disease, you will end up with both false positives and false negatives. This means that fat people without actual health risk factors such as high blood pressure or high cholesterol are more likely to be given unnecessary medical treatment (i.e., false positive). On the other hand, people with a low body mass index (BMI) will tend to receive no medical intervention even though they may actually have health risk factors (i.e., false negative).

The Easter Bunny just found out that he, too, is a myth.

The Easter Bunny just found out that he, too, is a myth.

So those who can say, “Oh, I can eat anything and not gain weight,” are missing the significance. It’s not so much a matter of whether or not you gain weight, but that nutrition and exercise affect your health independent of weight. Poor nutrition is not advisable for anyone – but is often glossed over with lower-weight people. When a thin person eats a double ice cream sundae, bystanders marvel, “Where do you put it?” But give that same sundae to a fat person, and she will be chastised.

Where health is concerned, what we do is much more important than what we look like. Activities that promote good health, such as exercise; eating nutritious food; getting enough sleep; and positive personal relationships are what we should strive for, no matter what the scale says. In short, fat (even obese!) people can be living healthy lives, and thin people can be living unhealthy lives.

It’s a new way of thinking – to separate weight from health habits – but it’s crucial. Conflating weight with health is doing a disservice to everyone. No matter what their weight.

For an in-depth exploration of weight science:
Bacon, L., & Aphramor, L. (2011). Weight science: evaluating the evidence for a paradigm shift. Nutrition Journal, 10(9).

Bunny photo courtesy of Gratisography
April Food Day On 1st Day Of Month – Image courtesy of Keerati at