Some big studies that looked at lots of people who ate less saturated fat didn’t find that they lived longer or had fewer heart attacks, which makes people question why we’ve been told to avoid foods like butter and cheese for so long.

Eating less saturated fat doesn't seem to reliably help people live longer or avoid heart disease deaths, whether they're healthy or already have heart disease.

Eating less saturated fat—like butter or fatty meats—doesn’t seem to lower the risk of dying from heart problems or other causes, even after years of doing it, according to a review of nine big studies.

Multiple large-scale meta-analyses of prospective cohort studies demonstrate no statistically significant association between dietary saturated fat intake and incidence of coronary heart disease or cardiovascular disease.

The official advice to eat less fat to avoid dying of heart disease isn't backed up by the long-term studies of large groups of people.

This review looked at data from over 347,000 adults followed for an average of 14 years — so if saturated fat had even a moderate effect on heart disease, this study would have been able to find it.