The pattern where both very low and very high body mass index increase death risk in heart disease patients holds true regardless of whether they smoke, are physically active, or have different education levels.

In people with heart disease, having a body mass index around 27 is linked to the lowest chance of dying from any cause, while both lower and higher BMIs are associated with higher risks.

If you’ve never smoked but have a very physically demanding job, your risk of dying from heart disease is more than three times higher than someone with a less active job — even if you’re otherwise healthy.