The review, led by Zoë Harcombe from the University of the West of Scotland, concluded that fat intake guidelines implemented in the US and UK in 1973 and 1980 with the aim reducing coronary heart disease (CHD) "should not have been introduced."
On both sides of the Atlantic, health authorities recommended that fat and saturated fat consumption be limited respectively to 30% and 10% of total energy intake.
Researchers from the University of the West of Scotland Cardiff Metropolitan University, University of South Wales, and Saint Luke's Mid America Heart Institute reviewed evidence from six RCTs available to US and UK authorities at the time of implementation that examined the relationship between dietary fat, serum cholesterol, and the development of CHD.
A total of 2,467 men - 1,227 in intervention groups fed a low-fat diet and 1,240 in control groups - participated in the trials.
Harcombe and her team found that "all-cause mortality was identical at 370 in the intervention and control groups."
There was also "no statistically significant difference" in deaths from CHD, with 207 in the intervention groups and 216 in the comparison groups.
"The results of the present meta-analysis support the hypotheses that the available RCTs did not support the introduction of dietary fat recommendations in order to reduce CHD risk or related mortality," the review concluded.
"Strong body of evidence"
This conclusion, published in the Open Heart journal, supports the existing "strong body of evidence to demonstrate the nutritional qualities of dairy products," said Dr Anne Mullen, director of nutrition, the Dairy Council.
"Public guidelines should be clear, recognisable and achievable," she said.
"An excess in consumption of saturated fat contained in any foods would not be a good, balanced diet but the reality is that anyone putting butter on their toast in the morning or drinking full-fat milk - unless they have a particular medical condition - can do so in the knowledge that these are nutritionally sound products."
"The overarching issue in terms of saturated fats is the amount rather than the existence of it in a particular product," Mullen concluded.
Scores of experts have meanwhile taken a different view on the review's findings...
Source: Open Heart doi:10.1136/openhrt-2014-000196
Title: Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis
Authors: Z Harcombe, J S Baker, S M Cooper, B Davies, N Sculthorpe, J J DiNicolantonio, F Grace.