After a series of hearings, Congress voted to enact the first set of Dietary Guidelines for Americans in 1977. Essentially, the guidelines recommended that Americans reduce their intake of saturated fat found in eggs, milk, meats and cheese, and replace those calories with carbohydrates.
More than 30 years later, a group of researchers from the United States and the United Kingdom reviewed the data available at the time to determine if there was sufficient evidence to make these recommendations.
The review, published this month in the journal Open Heart, identified six studies published before 1983 that looked at the relationship between fat consumption and heart disease. Nearly 2,500 men participated in the trials. None of the dietary changes tested in the studies impacted participants risk of dying, either from heart disease or any other illness.
The researchers were also unable to find any randomized, controlled trials – the gold-standard of medical research – that were conducted before 1980 that linked diet and heart disease.
The reviewers concluded: “Dietary recommendations were introduced for 220 million U.S. and 56 million U.K. citizens by 1983 in the absence of supporting evidence.”
So what to eat instead? That’s a complicated question. Nutritionists agree that the 1977 guidelines led people to consume refined carbohydrates and sugar in place of fats, an unhealthy choice. The food industry latched onto the advice and filled grocery store shelves with low-fat products that also happened to be high in sugar, likely leading to higher rates of diabetes and obesity that we see now.
But an editorial that accompanies the most recent review makes the point that we shouldn’t let the pendulum swing too far in the other direction, consuming too much fat and making carbohydrates the enemy.
For now, the best advice we have is to eat a variety of whole grains, fruits, vegetables, and meats, and yes, some fat as well.