The evidence base for fat guidelines: a balanced diet
- Cardiology, Royal Berkshire NHS Foundation Trust, Reading, UK
- Correspondence to Dr Rahul Bahl;
Harcombe et al have conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) that would have been available to the regulatory committees in the USA and the UK when guidelines on dietary fat intake were introduced (in 1977 and 1983, respectively). They found no evidence from RCTs to support the introduction of these guidelines, which leads the authors to question whether they should ever have been introduced in the first place. 1 The negative result of the meta-analysis is unsurprising. The most up-to-date review of cohort and RCT studies draws a similar conclusion that there is very limited evidence to support current guidance.2 However, whether this means that changes to the health policy should be made, is a more complex question.
There is evidence to say that individual interventions to change behaviour and modify risk do not lead to changes in hard clinical end points. Most of the trials relied on dietary advice to situate participants within their different groups, with some also providing supplements and only one trial (the LA veterans study) actually …