“Government dietary fat recommendations were untested in any trial prior to being introduced,” writes Zoe Harcombe of the University of the West of Scotland, lead author of the study. Despite this, “to date, no analysis of the evidence base for these recommendations has been undertaken,” which is what prompted Harcombe and her team to conduct their investigation. . . .
Beyond reducing fat intake, the Dietary Goals also urged a reduction in the consumption of salt and sugar, whose deleterious health effects have been far better established. [For salt, maybe not.]
Though they haven’t materially changed since their introduction, the low-fat dietary guidelines have been undermined by subsequent research that has indicated that low-carbohydrate diets are more effective at promoting better health than low-fat ones. The longstanding advice to increase the consumption of carbohydrates as a way to offset the reduction in fat may now be proving Dr. Hegsted’s assertion wrong: there could well be downsides to embracing the McGovern report’s full recommendations.
The conclusion of the Harcombe study is stark and unequivocal: “The present review concludes that dietary advice not merely needs review; it should not have been introduced.”