The year was 1977. The US Senate Select Committee on Nutrition and Human Needs, led by Senator George McGovern, issued the first Dietary Goals for Americans, thereby marking the beginning of the low-fat era of dietary nutrition, arguably the most misguided period of government-led nutrition ever. After 38 years, however, the low-fat era might officially end later this year.
The Dietary Goals evolved into the Department of Health and Human Services’ (HHS) and Department of Agriculture’s (USDA) Dietary Guidelines for Americans, later represented as the Food Pyramid and, currently, as MyPlate. The Guidelines’ dominant theme has been that calories consumed should equal calories expended. And since fat has 9 calories per gram, compared to only 4 for both carbohydrates and protein, fat became typecast as the “bad guy” nutrient.
Furthermore, since saturated fat and dietary cholesterol have been thought to promote cardiovascular disease, the Guidelines have recommended restricting fat to less than 30% (revised to 35% in 2005) of total calories. Consequently, carbohydrates, particularly refined carbohydrates and added sugars, came to replace healthy fats in Americans’ diets.
USDA and HHS update the Guidelines once every five years and the next revision is forthcoming later this year. Historically, the Guidelines echo the Dietary Guidelines Advisory Committee (DGAC) report, written by appointed scientists who systematically review the scientific literature on nutrition. The current DGAC report, published earlier this year, features two monumental deviations from the current Guidelines.
First, as we previously reported, the DGAC no longer considers dietary cholesterol to be a “nutrient of concern.”1 Previously, they recommended limiting cholesterol to 300 mg/day, but now acknowledge, “available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol.”
Second, the DGAC recommends removing upper limits on total fat consumption with respect to total calories. “In low fat diets,” they write, “fats are often replaced with refined carbohydrates and this is of particular concern because such diets are generally associated with dyslipidemia.”2 Reducing total fat (replacing total fat with overall carbohydrates), they conclude, “does not lower cardiovascular disease risk.”
So what does all this mean? If USDA and HHS follow the DGAC’s recommendations, the low-fat era will finally end and, going forward, Americans will have more scientifically accurate information about fat and will likely embrace healthful, fatty foods more readily.