Setting-upsetting the stage for new US dietary guidelines

Controversial ground has been laid for the 2015 Dietary Guidelines for Americans with the Dietary Guidelines Advisory Committee (DGAC) releasing on February 19 its non-binding recommendations to the USDA and the Dept of Health and Human Services (including the FDA). Although consumers rarely pay direct attention to the guidelines, the first to be issued in five years, they will influence everything from school lunches to doctors’ dieting advice.

The DGAC’s advice has already set off some contentious debate, particularly over warnings about meat and added sugars, their recommendations that eggs and coffee are okay and that the environmental impact of food should be considered when choosing foods.

The DGAC’s report amounts to a scientific update regarding what is known about healthy eating. For the first time, it is recommending that the government should consider the environment when telling Americans what they should eat, a move that could have a significant impact on the amount of meat people eat.

It also, for the first time, addressed concerns about coffee, saying that there is strong evidence that moderate consumption is not associated with long-term health risks.

The panel also reversed decades of warnings about dietary cholesterol. For years, the Dietary Guidelines have advised Americans to consume no more than 300 milligrams of cholesterol a day, a warning that limited egg consumption for many Americans. The limit arose from the belief that eating cholesterol would lead to high levels of “bad” cholesterol in the blood. But, the group concluded, no such warning is necessary.

“Available evidence shows no appreciable relationship between consumption of dietary cholesterol and [blood] cholesterol,” the report found.

The bulk of the report, which runs to 571 pages, outlines reams of scientific evidence about what’s good to eat. And in terms of dietary advice, it can be summarised as follows:

  • A healthy diet is rich in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts.
  • It is moderate in alcohol
  • And it is lower in red and processed meat, and low in sugar-sweetened foods and drinks and refined grains.

The government has published  dietary guidelines since 1977, and during that time, those guidelines did not avert what many nutritionists consider a dietary disaster – the nation slipped into an obesity epidemic.

“In the past, we haven’t been able to change the way people are eating very much,” said Alice Lichtenstein, a committee member and nutrition professor at Tufts University. “One of the major focuses of this report is, rather than nutrients, the whole diet.”

So in compiling the evidence on diet and health, the group took a different tack from previous committees. Rather than focusing on the health effects of individual nutrients, it focused on how entire diets affect health.

The committee reviewed studies that looked for associations between diets and major diseases such as cancer, heart troubles and diabetes.

With regard to what people ought to eat, their research turned up the most consistent evidence for the health benefits of fruits and vegetables. The evidence for the benefits of whole grains was only slightly less consistent.

Warning on added sugars

The panel singled out added sugars as one of its major concerns. Previous dietary guidelines have included warnings about eating too much added sugar, but for the first time the panel recommended that Americans limit it to no more than 10 percent of daily calories — roughly 12 teaspoons a day for many adults — because of its link to obesity and chronic disease.

Americans consume 22 to 30 teaspoons of added sugar daily, half of which come from soda, juices and other sugary drinks. The panel said sugary drinks should be removed from schools, and it endorsed a rule proposed by the FDA that would require a distinct line for added sugars on food nutrition labels, a change the food and sugar industries have aggressively fought.

Many experts, including some who disagreed with the panel’s cautions on salt and saturated fat, applauded its stronger stance on added sugars.

“That was one of the high points of these guidelines, and something that was sorely needed,” said Dr Ronald M Krauss, the director of atherosclerosis research at Children’s Hospital Oakland Research Institute. “There is a striking excess of added sugar intake in all age groups across the population.”

Other critiques

The DGAC included the vegetarian diet as an example of what it called a healthy eating pattern, noting that a plant-based diet is also more sustainable, with less of an impact on the environment. But critics question whether the guidelines might overstep the mandate to focus on health and nutrition.

“It appears the advisory committee was more interested in addressing what’s trendy among foodies than providing science-based advice for the average American’s diet,” said Howard Hill, a veterinarian and president of the National Pork Producers Council.

The advisory panel was also criticised for its advice against saturated fat, which has been challenged by several recent studies. Dr James DiNicolantonio, a cardiovascular scientist at Saint Luke’s Mid America Heart Institute, said that replacing saturated fat with the polyunsaturated fats in vegetable oils could worsen blood cholesterol levels and raise cancer and heart disease risk.

“The recommendations on saturated fat are a farce,” he said.

Adele Hite, a registered dietitian and spokeswoman for the nonprofit Healthy Nation Coalition, said that in the decades since their inception, the guidelines had played a direct role in the explosion of obesity and chronic disease by steering people away from nutritious whole foods like meat, eggs and butter.

Since the 1980s, Americans over all have been eating more grains, produce, cereals and vegetable oils, while generally lowering their intake of red meat, whole milk and eggs, Hite said, and yet the population is fatter and sicker than ever.

“Despite the unavoidable conclusion that the guidelines have failed in some fundamental way,” she said, “the response from the advisory committee seems to be that an even more restricted list of acceptable foods will, this time around, do the trick.”

The DGAC, composed entirely of academics, met publicly throughout 2014. It found that several nutrients are underconsumed: vitamin A, vitamin D, vitamin E, vitamin C, folate, calcium, magnesium, fibre, and potassium. For adolescent and premenopausal females, iron also is a shortfall nutrient.

The committee took no stand on the dangers of highly caffeinated energy drinks nor on non-nutritive sweetener aspartame, both of which were mentioned in the report.

Now that the DGAC has completed its recommendations, HHS and USDA will review the report, along with comments from the public – including other experts – and input from other federal agencies before publishing the final updated guidelines towards the end of 2015.

Additional reading:

Nutrition panel calls for less sugar and eases cholesterol and fat restrictions

Dietary guidelines shouldn’t be this controversial: Prof Marion Nestle

Top nutritional panel: Stop eating so much meat – to protect the environment

Five industry winners, losers in the food guideline report

The govt’s bad diet advice: Nina Teicholz