Every five years the US government puts forth new dietary guidelines. The reaction tends to split between disappointment with the lack of change and outrage when recommendations actually do change – how come we were advised something that's now deemed untrue? And if experts can’t be certain and consistent why bother with dietary guidelines at all?
The government’s guidelines are based on nutrition experts’ (The Dietary Guidelines Advisory Committee or DGAC) recommendations, and their science-based report came out last Thursday. Let’s see if we can find something to get angry about.
What’s new, what’s old?
Here’s the advice in a nutshell:
“The overall body of evidence examined by the 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meat and low in sugar-sweetened foods and drinks and refined grains."
This does sound familiar, doesn’t it? More plants, less meat, less sugar. Vegetables and fruit are most consistently identified as the food of healthy people.
Regarding sugar fat and salt:
“The DGAC encourages the consumption of healthy dietary patterns that are low in saturated fat, added sugars, and sodium. The goals for the general population are: less than 2,300 mg dietary sodium per day (or age-appropriate Dietary Reference Intake amount), less than 10 percent of total calories from saturated fat per day, and a maximum of 10 percent of total calories from added sugars per day."
The news here is that the committee departs from the vagueness of past reports and puts an upper limit on sugar consumption – 10 percent of total calories – and recommends adding a line for added sugar in the nutrition panel of packaged food to help consumers comply.
Previously, expert advice to lower fat intake was conveniently interpreted as permission to increase carbs – many times refined carbs – to fill the gap. Well, that’s not what the doctor ordered, and to make things clearer (emphasis mine):
“Sodium, saturated fat, and added sugars are not intended to be reduced in isolation, but as a part of a healthy dietary pattern that is balanced, as appropriate, in calories. Rather than focusing purely on reduction, emphasis should also be placed on replacement and shifts in food intake and eating patterns. Sources of saturated fat should be replaced with unsaturated fat, particularly polyunsaturated fatty acids. Similarly, added sugars should be reduced in the diet and not replaced with low-calorie sweeteners, but rather with healthy options, such as water in place of sugar-sweetened beverages.”
To eat better one needs to change dietary pattern, not reach out to the processed food whose label brags it’s free of the latest dietary villain. Low sodium and low saturated fat foods aren’t necessarily better for you.
One of the things that has changed in this report is that it’s moving away from putting an upper limit for cholesterol, stating that:
“Available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol... Cholesterol is not a nutrient of concern for overconsumption.”
Egg lovers who limited themselves to two eggs a week may be upset. Some say the egg industry might be behind this shift. Others point to the studies cited by the committee; those show that most people don’t respond dramatically to low cholesterol diets, and that these diets don’t improve outcomes in most analysis.
What’s this advice good for?
The advisory committee’s recommendations inform the government’s guidelines, and those affect policies, action and choices. They affect everything from school lunches to SNAP to the food industry, and also the way we personally fill our plate.
We have to eat something, so we need the best, most unbiased evidence to inform what we should eat. Let’s also remember that two-thirds of the US population is overweight or obese, and healthier diets could prevent many of the chronic diseases we’re afflicted with. Yes, we do need help.
That little changes from report to report is quite reassuring. There are many ways to eat healthy, and they seem to all converge around eating more plants, less processed food and moderation.
When pieces of advice do change don’t be upset. Science is never static. Our pursuit of the truth is a journey, and new, many times better data brings us closer to it. Today’s cars are infinitely safer than the ones sold in the 80’s, despite all the recent recalls. The scientific method moves us closer to the answer, but it does take time and further study, and nutrition study is both young and very difficult.
I think it’s wise to have a healthy, enjoyable food pattern. I don’t think you have to listen to the noise and the fine details. Those change, but the essence does remain the same, and change and discovery is what makes things interesting.