In the 2015-2020 Dietary Guidelines for Americans, the USDA and HHS recommend that we limit our saturated fat intake to no more than 10% of total calories. The Dietary Guidelines Advisory Committee lists saturated fat as a “nutrient of concern” and asserts that evidence linking saturated fat consumption to cardiovascular disease is “strong.”
In the real world, the debate regarding saturated fat and heart disease is far from settled. In 2012 Hoenselaar published an article in the journal Nutrition stating that the conclusions made by the various leading advisory committees regarding dietary saturated fat and cardiovascular disease were not in accord with the available literature (1). By 2012 there were already a meta-analysis and two major reviews that did not find an association between dietary saturated fat and heart disease (2,3,4).
Another systematic review and meta-analysis in 2014 by Chowdhury, et al., further concluded that current evidence does not support guidelines for low saturated fat consumption in regards to heart disease (5).
The Women’s Health Initiative, a clinically controlled study including 49,000 people, found no benefit in achieving significantly lower saturated fat intakes in regards to incidence of coronary heart disease events or total cardiovascular disease (6).
DiNicolantonio, Lucan, and O’Keefe (2015) stated that in regards to coronary heart disease, sugar is more of a problem than saturated fats, and that dietary guidelines should move away from recommendations to reduce dietary saturated fat and focus more on sugar (7).
Another systematic review and meta-analysis by Harcombe, Baker, and Davies (2017) further concluded that the epidemiological evidence to date does not support the dietary guidelines to reduce saturated fat (8).
One potential danger of these recommendations, as Parodi (2016) points out, is that in lieu of a high-fat, high saturated fatty acid diet, many people will gravitate towards a low-fat diet high in refined carbohydrate, which is likely to lead to high triglyceride levels, high levels of small dense LDL particles, and lower HDL, all of which are risk factors for CHD (9).
Although the Scientific Report specifically recommends dietary patterns rich in whole grains and low in refined grains, the final guidelines are distilled down to a recommendation that at least half of all grains consumed be from whole grains. Given the controversy surrounding the recommendations for saturated fat in regards to cardiovascular disease, I find it odd that the limit for saturated fat would be hard and fast at 10% of total calories, while the guidelines allow for up to half of total grains consumed to come from refined sources.
(1) Hoenselaar, R. (2012). Saturated fat and cardiovascular disease: The discrepancy between the scientific literature and dietary advice. Nutrition, 28, 118-123.
(2) Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr, 91, 535-46.
(3) Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. (2010). Saturated fat, carbohydrate, and cardiovascular disease. Am J Clin Nutr, 91, 502-9.
(4) Hooper L, Summerbell CD, Thompson R, et al. (2012), Reduced or modified dietary fat for preventing cardiovascular disease. Cochrane Database Syst Rev; 5:CD002137.
(5) Chowdhury R, Warnakula S, Kunutsor S, et al. (2014). Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis. Ann Intern Med, 160, 398-406.
(6) Teicholz, N. (2015). The scientific report guiding the US dietary guidelines: is it scientific? BMJ, 351, h4962.
(7) DiNicolantonio, J.J., Lucan, S.C., and O’Keefe, J.H. (2015). The Evidence for Saturated Fat and for Sugar Related to Coronary Heart Disease. Progress in Cardiovascular Diseases, 58, 464-472.
(8) Harcombe, Z., Baker, J.S., and Davies, B. (2017). Evidence from prospective cohort studies does not support current dietary fat guidelines: a systematic review and meta-analysis. Br J Sports Med, 51, 1742-1748.
(9) Parodi, P.W. (2016). Dietary guidelines for saturated fatty acids are not supported by the evidence. International Dairy Journal, 52, 115-123.