- Researchers investigated how global dietary patterns changed between 1990 and 2018.
- They found that by 2018, the diet was becoming modestly healthier.
- They concluded that dietary recommendations should be based on localized dietary data.
Data show that poor diet is responsible for around 26% of preventable mortality worldwide. There is evidence that different foods and nutrients have synergistic and complementary effects when eaten together
While what constitutes an optimal dietary pattern is largely established and validated, it remains unclear how frequently it is consumed worldwide.
Previous studies were limited to small subgroups of countries and did so usually does not include people under 25 years of age.
Studies that examined the dietary habits of different countries across a wider age range could improve dietary guidelines and recommendations.
Recently, researchers analyzed global, regional, and national dietary patterns and trends among adults and children from 185 counties.
They found that the diet became somewhat healthier between 1990 and 2018, although the extent varied from country to country.
“In general, a healthy diet has become more affordable as countries have become richer,” Dr. Boyd Swinburn, professor of epidemiology and biostatistics at the University of Aukland, who was not involved in the study, told Medical News Today.
“The globalization of food also means that the diversity of whole foods has increased, which is good. But the balancing forces of ultra-processed foods that take over whole foods and increasing wealth inequalities are leading to an unhealthier diet,” Dr. Swinburn added.
The study appears in Nature Food.
Global analysis of nutritional data
In addition to biomarker surveys, the researchers collected data from nationally and subnationally representative surveys on individual food intake.
In total, they collected data from 1,248 nutrition surveys from 188 countries. Among the surveys, 73.9% included data on children aged 0 to 19 and 64.5% of adults aged 20 and over.
The researchers received data on individual dietary intake of up to 53 foods, drinks and nutrients as well as demographic data such as age, gender, education and urban or rural residence.
The researchers used the Alternative Healthy Eating Index (AHEI) to define a healthy diet. Victoria Miller, Ph.D., research assistant at PHRI Population Health Research Institute and Visiting Scientist at Tufts University, one of the study’s authors, told
“The AHEI recommends that individuals consume lots of fruits, vegetables, whole grains, nuts and legumes, as well as polyunsaturated fats and omega-3 fats, and limited amounts of red and processed meats, sugar-sweetened drinks, and sodium.”
end, the researchers organized diets on a scale of 0 to 100, with 0 being a poor diet and 100 being an optimal diet.
They found that the global AHEI score rose slightly by 1.5 points between 1990 and 2018 — from 38.8 in 1990 to 40.3.
They also found that in 2018, only ten countries, accounting for less than 1% of the world’s population, had nutritional values of 50 or more. These included Vietnam, Iran, Indonesia and India with averages of 54.5.
countries with the lowest scores included Brazil, Mexico, the United States and Egypt, with scores ranging from 27.1 to 33.5.
The researchers found that the average AHEI scores in 2018 were similar for children and adults: between 38.2 and 42. However, in most regions, people under 5 and 75 years of age tended to have the highest AHEI scores.
They further wrote that children worldwide tended to consume less fruit, non-starchy vegetables, and omega-3 seafood than adults. However, they also consumed more sodium and polyunsaturated fats than adults.
The researchers also found that the university degree was associated with a higher AHEI score in most regions except the Middle East, North Africa and sub-Saharan Africa, where they did not observe any differences.
Improving dietary choices
Asking how these results could improve dietary choices around the world, Dr. Miller said:
“Our findings are useful for designing and implementing future research and national policies to improve nutritional quality. Although South Asia and Sub-Saharan Africa had the highest nutritional quality in 2018, the consumption of fruits, vegetables, legumes/nuts, omega-3 fat from seafood, and polyunsaturated fats was anything but optimal in these regions. Measures to increase the intake of products, seafood and vegetable oils will have the biggest impact on nutritional quality in these countries.”
“In Asia, Latin America and the Caribbean, we’ve noticed that red/processed meats and sodium have increased over time, and measures focused on reducing the intake of these foods and nutrients will significantly improve nutritional quality,” she added.
“Low consumption of unhealthy foods and nutrients, such as sugar-sweetened drinks, red/processed meats, and sodium, resulted in higher nutritional quality in many countries, including Vietnam. In the US, a double focus on increasing healthy foods (fruits, vegetables, vegetable oils) and reducing unhealthy foods (sugar-sweetened drinks, sodium) is needed to improve nutritional quality,” she noted.
Dr. Marco Springmann, senior researcher on environment and health at Oxford University, who was not involved in this study, also told MNT:
“The study also underlines that there has been little progress worldwide in improving nutrition. This should be a wake-up call for policymakers who routinely dismiss the need for a progressive food policy as too much market interference.”
“Without clear policies that would enable citizens to make healthy and sustainable dietary choices, we risk having another decade without progress in improving nutrition and the associated health and environmental impacts,” he added.
The researchers concluded that their findings highlight the need for specific national and sub-national measures to improve nutrition.
Dietary Study Limitations
Asked about the limitations of the study, Dr. Swinburn said: “Data on diets is notoriously challenging. There are always massive sub-reports — around 20% of calories under optimal data collection conditions are never recorded.”
“However, if you take a larger approach like this, you’ll see patterns that can tell you very useful things about the underlying changes over time and the differences between populations,” he added.
Dr. Rob M. van Dam, professor of exercise and nutrition sciences at George Washington University’s Milken Institute School of Public Health, also told MNT: “The limitation of these findings is that the survey tools and accuracy of the data varied from country to country.
“In addition, the dietary quality indices used in the study were developed in high-income countries to prevent chronic illness, but may be less suitable for low-income countries where nutritional deficiencies are common,” he added.
Salim Yusuf MD, D. Phil, Distinguished Professor of Physiology and Pharmacology at McMaster University who was not involved in the study, agreed that guidelines based on data may not apply to most other regions of the world. He found that malnutrition is a challenge for many, in addition to appropriate food choices. He added that cultural habits, tastes, and costs also influence what people eat.