Before the government told everyone to eat less fat, no study had actually tested whether eating exactly that much fat helped people live longer.
Scientific Claim
No randomized controlled trial conducted before 1983 tested the specific dietary fat recommendations of ≤30% total fat and ≤10% saturated fat before they were adopted by U.S. and U.K. public health authorities.
Original Statement
“Government dietary fat recommendations were untested in any trial prior to being introduced. ... No RCT had tested the dietary fat recommendations; no RCT concluded that dietary guidelines should be introduced.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
This is a factual claim about the absence of trials matching specific criteria, which the systematic review directly assessed. The language is precise and supported by the exclusion criteria and study selection process.
Evidence from Studies
Supporting (1)
Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis
Before the government told people to eat less fat in the late 1970s and early 1980s, no big scientific experiments had tested whether those exact rules actually prevented heart disease — and this study proves it.