When it comes to health, most people assume that thinner is always better. But new research from Denmark challenges this long-held belief, showing that being too thin could actually be more dangerous than carrying some extra weight.
What the Study Found
Researchers followed more than 85,000 Danish adults, most of them women with a median age of 66. Over a five-year period, they carefully analyzed how body mass index (BMI) related to the risk of dying early. Surprisingly, the results showed that those with a BMI below 18.5, considered underweight, were nearly three times more likely to die prematurely than people whose BMI was in the upper-normal range of 22.5 to 25. Even individuals at the lower end of the so-called “normal” category, between 18.5 and 22.5, carried a significantly higher risk of death compared to those closer to 25.
Overweight Did Not Always Mean Danger
One of the most striking findings was that people in the overweight range, and even those with mild obesity, did not necessarily face higher risks than the upper-normal group. In fact, their mortality rates were often similar. It was only at more extreme levels of obesity, particularly a BMI above 40, that the risk of dying early more than doubled.
Why Being Underweight Is Risky
Scientists suggest that part of the explanation could be reverse causation, meaning that people who are very thin might already be struggling with undiagnosed illnesses. Moreover, BMI alone is not a perfect measure since it does not take muscle mass or fat distribution into account. Still, the findings raise important concerns about the dangers of underweight, especially in older adults.
Rethinking the “Thinner Is Better” Myth
This study highlights that health is not just about lowering the number on the scale. Maintaining a healthy, balanced weight may be far more important than striving for extreme thinness. The results call for a shift in public health messaging, moving beyond the idea that weight loss is always the healthiest path.
