An unhealthy diet is a major risk factor for non-communicable diseases globally, including Type 2 diabetes, cardiovascular disease, and certain types of cancer. In the U.S, poor diet was estimated to be the leading cause of death and the third leading cause of disability-adjusted life-years lost. As a result, evaluating the overall trends in diet is important to identifying challenges and opportunities for improving the diet of all U.S. adults. The calorie needs of the human body are mainly supplied by three dietary macronutrients: carbohydrate, fat, and protein. Changes in the economy, nutrition-related policies, and food processing methods can affect the nutrient composition and diet quality at the population level. Recently, the results of nine cycles of the National Health and Nutrition Examination Survey (NHANES), which examined trends in the U.S. diet from 1999 to 2016, were published.
The survey found that from 1999 to 2016, the macronutrient composition of the diet of U.S. adults improved. It found that previously observed trends in the U.S. diet from 1971 to 2000 were substantially reversed. If you are old enough to remember the years from 1971 to 2000, you might recall the emphasis on reducing dietary fat. Many products were marketed as “low-fat” or “no fat.” If you decrease the level of one macronutrient, you must increase the level of another one. From 1971 to 2000, fat consumption was lowered while carbohydrate consumption (refined grains and sugars) increased.
That unhealthy trend was reversed from 2000 to 2016 as the survey found that the macronutrient composition in U.S. diets improved. It found declines in low-quality carbohydrates (mostly added sugars) and increases in high-quality carbohydrates (mostly whole grains), plant proteins (whole grains and nuts), and polyunsaturated fatty acids. Unfortunately, the proportions of energy from low-quality carbohydrates remained higher than recommended as did the consumption of saturated fats. After 2000, shifts in scientific evidence and dietary recommendations promoted the benefits of healthy fats and plant sources of protein, and the harms of low-quality carbohydrates like added sugars and refined, or white, rice and flour. In addition, the growing popularity of specific diet patterns like Atkins, paleo, and vegan/vegetarian may have contributed to the observed positive dietary trends.
Dietary challenges remain, however. U.S. adults still consume too much low-quality carbohydrates (refined grains, fruit juices and sodas, and potatoes). Also, protein intake is still derived from animal foods such as unprocessed red meat and processed meats as opposed to heathier seafood and plant sources. Previous studies have shown that red meat and processed meat are associated with poorer health outcomes. Plus, the consumption of saturated fats remains above the recommended level of 10 percent of energy intake. Finally, U.S. adults with low income or low educational attainment did not show the overall improvement in diet that the survey found.
If you are looking for a healthy diet to follow, I recommend that you research the Mediterranean diet. It has all the positives that this survey found without the negatives. It is high in seafood, whole grains, nuts, seeds, veggies, olive oil, and legumes, and has low saturated fat and no red or processed meats.