It’s been nearly two decades since the nation’s nutrition experts disavowed their disastrous advice to shun dietary fat and urged Americans to focus instead on whole grains, nuts and healthful fats. And new research shows we’ve been listening — a little bit.
On a scale of 1 (dreadful) to 100 (perfect), the quality of the average American’s diet has risen from 50.5 in 1999 (decidedly meh) to 52.5 in 2016 (still pretty meh).
For public health officials, this improvement may not merit so much as a glass of sparkling water, especially since Americans with the least education and the lowest incomes showed no improvement at all.
The findings were drawn from nine rounds of surveys conducted between 1999 and 2016 by the Centers for Disease Control and Prevention. As part of the National Health and Nutrition Examination Survey, a nationally representative cross-section of American adults answered detailed questions about everything they had eaten in the previous 24 hours. Roughly 44,000 Americans ages 20 and up participated in one of the surveys.
The survey data show that at least some Americans have turned away from the nutrition establishment’s ill-fated view that dietary fat posed the greatest risk to human health. When consumers heard that advice, beginning in the 1970s, they responded by gorging on fat-free manufactured foods that replaced fat with sugar and empty carbs.
In 1971, carbohydrates accounted for 42% to 45% of the calories consumed by Americans each day, on average. By 1999, that share had increased to 52%.
As the nation came to learn, however, simple carbohydrates and added sugars are empty calories that cause rapid weight gain and metabolic problems such as diabetes. After nearly three decades, nutrition experts came up with a new message: Saturated fats — the kind that are plentiful in red meats and processed animal proteins — should be limited and replaced wherever possible by the polyunsaturated fats found in nuts and legumes, vegetable oils and fish.
By 2016, the share of Americans’ daily intake represented by carbs fell back to 50%.
The “fat-free” craze also saw fat consumption fall from about 37% in 1971 to 32% in 2000. After the dietary advice was updated, fat intake rose slightly, to 33% of calories in 2016.
The findings were published Tuesday in the Journal of the American Medical Assn.
The improvement may reflect the “shifts in scientific evidence and dietary guidelines” that began around 2000, the study authors wrote. On the other hand, it may simply reflect the churn of new diet fads, including Atkins, Paleo, low-carb and vegan/vegetarian lifestyles.
Make no mistake, however: We are still a country that loves to wash down its cheeseburgers and French fries with a sugary soft drink, then reward ourselves with cookies.
Americans’ saturated fat intake stood at 11.9% of average calories in 2016, stubbornly above the 10% level recommended by experts.
Added sugars in food and beverages accounted for 14.4% of intake in 2016 despite admonitions in the federal dietary guidelines that no more than 10% of total calories should come from added sugar.
Among the other sobering facts: Fast-food sandwiches, burgers, tacos and pizza accounted for about 18% of Americans’ total calories in 2016, while desserts, sweet snacks, chips and crackers contributed an additional 17%.
On the plus side, the proportion of our daily energy intake from carbohydrates deemed to be of “low-quality” sank from 45.1% in 1999 to 41.8% in 2016. Meanwhile, the proportion of Americans’ average calorie intake represented by “high-quality” carbs, including whole grains and fresh fruits and vegetables, increased from 7.4% to 8.7% over the same period.
The findings show differences among racial and ethnic groups too. Non-Latino whites consume more alcohol, pizza and fast-food sandwiches (those collectively represent 24% of their total energy intake). Non-Hispanic blacks eat more salty snacks and sweet desserts (17% of total calories). And Latinos consume more sugar-sweetened beverages (8% of total energy) and the least alcohol.
Among low-income U.S. adults, and among those who didn’t finish high school, the shifts toward higher-quality carbohydrates and better fats registered only slightly, and the overall quality of their diets did not budge.
Public health efforts aimed at improving Americans’ diets “should focus on minimizing these differences,” wrote the study authors, a team from Harvard and Tufts University.
Better messaging from nutrition experts will help, according to an editorial that accompanies the JAMA study. But if Americans are to move toward greater adherence to the government healthful-eating guidelines, cooperation from the food industry is key.
Companies that sell food need to reduce the sugar, salt and saturated fats in their offerings, wrote Northwestern University population nutrition experts Linda Van Horn and Marilyn C. Cornelis. And they need to encourage consumers to buy and consume whole grains, fruits, vegetables and plant-based proteins, they added.