Diets are only slightly healthier than they were 30 years, according to a global study.
Researchers from the Friedman School of Nutrition Science and Policy at Tufts University investigated the eating habits of adults and children in 185 countries over three decades. They used the Alternative Healthy Eating Index, which ranks different diets on a scale of 0 to 100, with 0 representing heavy consumption of sugar and processed meats and 100 representing the recommended balance of fruits, vegetables, legumes/nuts and whole grains. They also used data from over 1,100 surveys from the Global Dietary Database, a large, collaborative compilation of data on food and nutrient consumption levels worldwide.
They concluded the average global in 2018 was 40.3, 1.5 points higher than in 1990. European countries were included in the region defined as “high-income countries” which also includes North America and Australia. In 2018, the mean score for high-income countries was 37.8, 3.2 points higher than in 1990.
There were some notable variations by country, with nutritious options becoming more popular in the United States, Vietnam, China, and Iran, and less so in Tanzania, Nigeria, and Japan.
Regionally, averages ranged from as low as 30.3 in Latin America and the Caribbean to as high as 45.7 in South Asia. Only 10 countries, representing less than 1% of the world’s population, had scores over 50. The world’s highest scoring countries were Vietnam, Iran, Indonesia and India, and the lowest scoring were Brazil, Mexico, the United States and Egypt.
Women were more likely to eat recommended diets than men, and older adults more so than younger adults.
Poor diet is a leading cause of illness, responsible for 26% of preventable death worldwide. But the researchers said little has been known about differences in dietary quality by demographics such as age, sex, education, or proximity to urban areas.
The researchers claimed the study is one of the most comprehensive estimates yet of global dietary quality and the first to include findings among children as well as adults.
They concluded the modest global gains highlight the challenges worldwide to encourage healthy eating.
“Intake of legumes/nuts and non-starchy vegetables increased over time, but overall improvements in dietary quality were offset by increased intake of unhealthy components such as red/processed meat, sugar-sweetened beverages, and sodium,” said lead author Victoria Miller from McMaster University in Canada, the senior author on the paper.
“Healthy eating was also influenced by socioeconomic factors, including education level and urbanicity,” she added. “Globally and in most regions, more educated adults and children with more educated parents generally had higher overall dietary quality.
“On average across the world, dietary quality was also greater among younger children but then worsened as children aged. This suggests that early childhood is an important time for intervention strategies to encourage the development of healthy food preferences.”
The researchers said that the study will enable nutrition researchers, health agencies, and policymakers to better understand trends in dietary intake that can be used to set targets and invest in actions that encourage healthy eating, such as promoting meals made up of produce, seafood, and plant oils.
Dr Dariush Mozaffarian from Tufts University, who led the research, said: “We found that both too few healthy foods and too many unhealthy foods were contributing to global challenges in achieving recommended dietary quality. This suggests that policies that incentivize and reward more healthy foods, such as in healthcare, employer wellness programs, government nutrition programs, and agricultural policies, may have a substantial impact on improving nutrition in the United States and around the world.”
The research team now plans to look at how different aspects of poor diets directly contribute to major disease conditions around the world, as well as modelling the effects of various policies and programs to improve diets globally, regionally, and nationally.
Reference
Global dietary quality in 185 countries from 1990 to 2018 show wide differences by nation, age, education, and urbanicity
Nature Food
DOI: 10.1038/s43016-022-00594-9