The case against saturated fat – Diet and Health Today

Introduction

A paper was published in the Annals of Internal Medicine on 16th December 2025. It was called “Effects of interventions aimed at reducing or modifying saturated fat intake on cholesterol, mortality and major cardiovascular events” (Ref 1). The sub-heading was “A risk stratified systematic review of randomised trials.” It was by Steen et al. The paper grabbed my attention for three reasons:

1) This is my home turf. For my PhD I did a systematic review (and meta-analysis) of randomised trials that had interventions aimed at reducing or modifying fat intake (not just saturated fat). The endpoints I reviewed were cholesterol, all-cause mortality and heart mortality (not just events). For my final paper I put the findings of my research team in the context of other research teams. There was remarkable consistency in finding nothing against saturated fat (I’ll present this fully below).

2) I could not see the point of this paper. Several teams have looked at this topic already (Ref 2). The randomised trials being reviewed were all published between 1965 and 2006. No new (large enough and long enough) trials have been conducted since then. No new (large enough and long enough) trials will be conducted. The abstract reported the background to the paper as “debates about optimal saturated fat advice continue.” Debates do continue, but they shouldn’t. Many research teams have examined the evidence and found nothing.

The January 2026 DGAs stated “More high-quality research is needed to determine which types of dietary fats best support long-term health.” I disagree. We need to ditch the bias and accept the overwhelming evidence that we have. Science should never be settled but this is as close to settled as nutritional science will get. Alas, the evidence doesn’t fit the anti-(saturated)-fat belief system and so it gets ignored.