The findings, published in September 2019 in the Journal of the American Medical Association, analyzed 44,000 American adults’ eating habits from 1999 to 2016. Researchers found that refined carbohydrate intake fell by 3 percent, but low-quality carbs, including white bread, white potatoes, and processed snack foods like crackers and cakes, still accounted for about 42 percent of the typical American’s daily calories. Healthy high-quality carbs that come from vegetables, fruits, and whole grains, including brown rice, whole-wheat bread, and whole-wheat pasta, made up only 9 percent of calories consumed. “I’m not at all surprised by these findings. We need to make some fundamental changes if we hope to fix our current diet,” says David L. Katz, MD, MPH, founder and president of the True Health Initiative, who is based in Derby, Connecticut, and was not involved in this research. “The simple fact is our culture does nothing to make eating well easy to understand, or to make healthy food choices the readily available default.” RELATED: 5 Tricks for Getting Enough Fruits and Veggies
How Researchers Analyzed Americans’ Diet
Authors used information gathered from a nationally representative group of people ages 20 and older from nine National Health and Nutrition Examination Survey (NHANES) cycles. Using information on race, gender, age, education, and family income, researchers sought to identify whether they could identify any trends in segments of the population. To evaluate individual diets, researchers relied on people to self-report what they ate in a 24-hour period. They used a “multiple-pass” method, which means after the respondents made an initial list of what they remembered eating, the interviewers probed for forgotten foods and gathered details of foods they consumed. They categorized foods accordingly:
High-quality carbohydrates include minimally processed foods, like whole grains, vegetables, fruits, and beans.Low-quality carbohydrates are foods like white bread, pastries, cookies, chips, and sodas.Animal proteins come from animals and include beef, pork, and chicken. Seafood like fish, shrimp, lobster, and crabs are also animal protein sources, as are eggs and dairy.Plant proteins are found in legumes such as black, lima, and pinto beans; soy products like tofu and tempeh; and nuts.Saturated fats are found in coconut and palm kernel oils, as well as butter. They are also found in most animal fats, like pork and chicken fats.Monosaturated fats are found in olive, canola, and peanut oil, are well as in avocados, and are part of animal fats from chicken, pork, and beef.Polyunsaturated fats are found in walnuts and pine nuts as well as sunflower, flaxseed, and corn oil. Omega-3 fatty acids that are found in some fatty fish, like salmon and trout, are a type of polyunsaturated fats.
Authors assessed the quality of a person’s diet using the Healthy Eating Index (HEI) from 2015. The U.S. Department of Agriculture (USDA) developed the HEI in 1995 as a way to measure how well Americans are following dietary recommendations. Scored from 0 to 100 (with 100 being a “perfect” diet), it’s composed of 13 components that incorporate different food groups and key recommendations, and the USDA has periodically updated it when guidelines have changed. RELATED: 10 of the Best Plant-Based Protein Sources
Americans Have Cut Back on Refined Carbs, but There’s Still Room for Improvement
Over the 18-year study, researchers observed the following trends:
Total carbohydrate intake went down 2 percent, and low-quality carb consumption was reduced by 3 percent.Uptake of higher quality carbs increased by only 1 percent.Total fat intake increased by 1 percent, and saturated fat made up about 12 percent of daily calories, 2 percent higher than the recommended daily amount.Protein intake from both animal and plant sources are increased, though not significantly.The HEI score increased 2 points, from 55.7 to 57.7; improvements were due to reduction of sugar consumption, though increased sodium intake was also noted.
Authors also noted trends in different populations:
Although most Americans improved their diet as a whole during the study, people older than 50, people with less than a high school education, and people living below the poverty line did not.Adults with higher income reduced low-quality carb intake by 4 percent compared with a 2 percent improvement for people living under the poverty line.
RELATED: What’s the Difference Between Good and Bad Carbs?
The Main Takeaways From the Report and Limitations
The results show that Americans are still consuming too many calories from low-quality carbohydrates, and more than the recommended amounts of added sugars and saturated fat, says Shilpa Bhupathiraju, PhD, co-senior author of the study, who is a research scientist at the Harvard T.H. Chan School of Public Health and also with Harvard Medical School and Brigham and Women’s Hospital in Boston. “Our study gives us insights into where we can improve our diets, where we can make further gains to optimize diet quality, and which subgroups to target so that we can eliminate disparities in healthy eating,” Dr. Bhupathiraju says. The popularity of the ketogenic and paleo diets could help explain why carbs went down slightly and saturated fat intake remained high, says Ariana Cucuzza, RD, at the Center for Functional Medicine at Cleveland Clinic in Ohio, who was not involved in the study. “A Mediterranean diet would have higher polyunsaturated fats, which are the healthy fats,” she says. Self-reported recall of diet is a limitation of the study, which is a shortcoming that the authors point out, says Cucuzza. “It can be hard to remember everything that you eat — you can have a bite or two here or a snack there that you forget to include,” she says. Right now, much of the food supply (like low-quality carbs) in the United States are manipulated to be addictive, says Dr. Katz. “There’s a lot of profit for some companies to keep the status quo when it comes to our current diet, but it comes at a massive health cost to the American public,” he says. RELATED: A Complete Mediterranean Diet Food List and 14-Day Meal Plan
How You Can Improve Your Own Diet Report Card
Making the grade with your food choices doesn’t have to be complicated. Bhupathiraju offers a few tips to get you started:
Swap the white bread and white rice with whole grain bread and brown rice.If you want a snack, trade-in potato chips and choose unsalted, roasted nuts instead.Seek out ways to eat more fresh whole fruits and vegetables.Find ways to replace red or processed meats with healthy sources of protein, such as nuts, legumes, seafood, and poultry.
If you really want to get an idea of what you’re eating, write it in a food diary or record it in an app in real time, she says. “Tracking what you eat with a food diary or app can help you see where you need to improve,” says Cucuzza. RELATED: The 14 Best Weight Loss Apps to Help You Torch Calories
