Global trends in NCDs attributable to dietary risks by year
Globally, 42.0 million (95%UI, 40.0-43.9) deaths were attributed to NCDs in 2019; among them, 7.9 million (95%UI, 6.5-9.8) accounted for 28.5% of all risk-related NCDs attributable to dietary risks, which had risen from 5.4 million (95%UI, 4.5–6.5) in 1990. The DALYs reached 187.7 million (95%UI, 156.0-255.4) in 2019, accounting for 25.2% of all DALYs of NCDs, which had increased from 132.0 million (95%UI, 111.3-156.8) in 1990 (Fig. 1).
The death rate, which was standardized by age and population, decreased from 154.3 (95%UI, 113.3-166.3) in 1990 to 101.0 (95%UI, 82.0 to 124.3) per 100,000 population in 2019. Males showed a similar trend to females, but higher rates of death and DALYs, from 1990 to 2019. In 2019, the mortality was 126 (95%UI, 102.7-154.5) among males and 80.0 (95%UI, 63.5-99.7) among females, and the DALY rate was 2911.5 (95%UI, 2402.2-3495.1) in males and 1709.6 (95%UI, 1395.6-2091.6) in females.
Global trends in NCDs attributable to dietary risks by gender, and age
Global gender differences showed more severe consequences (i.e., higher death and DALY rates) in males from 1990 to 2019 (Fig. 1). In 2019, 3.5 million (95%UI, 2.8-4.4) deaths were reported in women and 4.5 million (95%UI, 3.6-5.4) in men; the death rate per 100,000 population was 80.0 (95%UI, 63.5-99.7) in women and 126 (95%UI, 102.7-154.5) in men; the DALYs were 74.3 million (95%UI, 60.6-91.0) in women and 113.4 million (95%UI, 93.4-135.6) in men; and the DALY rate was 1710.0 (95%UI, 1396.1-2092.0) in women and 2911.5 (95%UI, 2402.2-3495.1) in men.
Trends in the numbers of deaths and DALYs attributable to dietary risks in both genders changed substantially with age (Fig. 2), with males peaking at age 70-74 with 567603.0 (95%UI, 449339.8-709158.629.1) deaths and females peaking at age 80-84, with 545559.2 (95%UI, 428615.7-697221.4) deaths. The number of DALYs peaked for both genders at age 65-69 with 23.9 million (95%UI, 19.3- 29.3), among females of a similar age at 9.3 million (95%UI, 7.4-11.6), and among males age 65-69 years at 15.0 million (95%UI, 12.118.2).
Before age 80, males had more deaths and DALYs, while females appeared to exceed those numbers after age 80; however, males in all age groups always had higher death and DALY rates. Deaths among those under 80 years accounted for 69.8% of all deaths and 88.9% of all DALYs in 2019. Males younger than 80 years bore a larger burden of deaths than females below age 80, as evidenced by their higher proportion of deaths (62.7% vs 37.2%) and DALYs (63.0% vs 37.0%). The adjusted death rates of both genders rose significantly with age, peaking at 4462.7 (95%UI, 3237.4-5833.8) per 100,000 population at 95 plus years, and the DALY rate peaking at 24418.9 (95%UI, 31914.7-18051.9) at 95 plus years.
Global trends in NCDs attributable to dietary risks by super regions and locations
Dietary risk-related death and DALY rates from NCDs have increased over the past 28 years in most of the GBD study super regions, except in the high-income areas, Central Europe, and the Caribbean region, which showed a decrease in 1990-2010 (Tables 1 and 2). The top three age-standardized mortality rates in the super regions were located in Eastern Europe, Oceania, and Central Asia, while the highest age-standardized DALY rates were located in Oceania, followed by Eastern Europe and Central Asia. The lowest mortality and DALY rates were observed in the high-income Asia Pacific region during 1990-2019. The disease burden was greater for men in most GBD super regions, compared to females, except in Oceania, Eastern Sub-Saharan Africa, and Western Sub-Saharan Africa.
The distribution of deaths and DALYs from NCDs, attributable to dietary risks by countries in 2019, are described in the global heat map (Fig. 3). The highest numbers of deaths and DALYs in the most populous nations were observed in China, with 2.0 million (1.5-2.6) deaths and 46.8 million (35.6 to 60.0) DALYs, followed by India (1.2 million deaths and 32.4 million DALYs), and the Russian Federation (0.4 million deaths and 8.5 million DALYs). The top three age-standardized death rates were found in Uzbekistan (483.6), the Solomon Islands (369.7), and Tajikistan (325.8). The top three countries with the highest age-standardized DALY rates were the Solomon Islands (9795.9), Uzbekistan (8378.9), and Nauru (7715.1). The countries with the lowest death and DALY rates were Japan (31.7) and Israel (778.9).
Global trends in NCDs attributable to dietary risks by SDI
The age-standardized rates of dietary-related deaths were highest in high-middle SDI regions, with an age-standardized rate of 176.44 (95%UI, 162.6-188.8), while the highest DALY rate was observed in low-middle SDI regions with a DALY rate of 2794.2 (95%UI, 2310.0-3400.2) in 2019. Both rates were lowest in high SDI countries, with a death rate of 56.5 (95%UI, 46.6-68.9) and a DALY rate of 1308.1 (95%UI, 1113.8-1547.0) in 2019.
Linear regression showed that the age-standardized mortality of both genders combined was negatively associated with SDI (r=-0.2598, P<0.001). The mortality was Y=-101.0*X+185.4. Similarly, the DALYs were negatively correlated with the SDI (r=-0.3071, P<0.001), and the DALY rate was Y=-2626*X+4305. Gender differences were calculated as the difference in the values of the males minus values of the females. Male gender was positively correlated with mortality (r=0.1446, P=0.039, Y=30.39*X+24.58) and a similar trend in the DALY rate (r=0.1455, P=0.042, Y=801.0*X+661.2) was found (Fig. 4A-B). The same results were found when we calculated the gender ratio as the males' rate divided by the females' rate, and the gender ratio was positively correlated with mortality (r=0.5761, P<0.0001, Y=0.9911*X + 0.8555), showing a similar trend in the DALY rate (r=0.5844, <0.001, Y=1.143*X + 0.8983) (Fig. 4C-D).
Leading causes of deaths and DALYs from NCDs attributable to dietary risks
Of the 23 NCDs attributable to dietary risks in the GBD data system, we analyzed the top 15 causes (Fig. 5). The top 10 causes of deaths or DALYs worldwide by NCDs attributable to dietary risks in 2019 were ischemic heart disease, stroke, diabetes mellitus, colon and rectal cancer, hypertensive heart disease, chronic kidney disease, tracheal, bronchial, and lung cancer, esophageal cancer, stomach cancer, and breast cancer. The mortality of ischemic heart disease ranked first in both males (78.7, 64.1-92.1) and females (48.3, 39.0-58.0). It was followed by stroke and colon and rectal cancer among males, and stroke and diabetes mellitus among females. Males and females shared the top three causes of DALY rates: ischemic heart disease, stroke, and diabetes mellitus. The rankings of five diseases on the numbers of deaths, including diabetes mellitus, tracheal, bronchial and lung cancer, chronic kidney disease, breast cancer, and atrial fibrillation and flutter rose by 72.3%, 39.0%, 72.2%, 37.5, and 69.9%, respectively, from 1990 to 2010, and by 31.6%, 14.7%, 27.9%, 20.4%, and 38.6%, respectively, from 2010 to 2019. However, the rankings on the numbers of deaths of colon and rectal cancer, stomach cancer, esophageal cancer, rheumatic heart disease, and cardiomyopathy and myocarditis declined in 1990-2019, and deaths from rheumatic heart disease showed a significant downward trend after 1990 (Fig. 5A).
The five leading causes of death from ischemic heart disease, stroke, colon and rectal cancer, diabetes mellitus, and hypertensive heart disease increased by 27.6%, 16.2%, 63.5%, 72.3%, and 3.5%, respectively, during 1990-2010. In 2010-2019, the five leading causes of death from ischemic heart disease, stroke, diabetes mellitus, colon and rectal cancer, and hypertensive heart disease increased by 16.9%, 8.4%, 31.6%, 24.6%, and 31.2%, respectively (Fig. 5A). The ranking of diabetes rose from 4th to 3rd. A similar trend was found in the numbers of DALYs, with an 85.2% and 34.3% increase during the two periods, respectively. The top five causes of DALYs remained stable in the two periods (Fig. 5B).
Leading risks of deaths and DALYs from NCDs attributable to dietary risks
The top five dietary risks for death or DALYs attributable to NCDs remained stable during the two periods. These risks during 1990-2019 included diets high in sodium, low in whole grains, low in legumes, low in fruits, and high in red meat. Diets high in trans fats increased significantly during the two periods by 17.9% and 18.3% respectively, from a ranking of 8th to 6th. The other three diet risks, including diets low in nuts and seeds, low in polyunsaturated fatty acids, and low in omega-3 fatty acids moved up one place during the past 29 years. The rankings of diets low in nuts and seeds moved from 9th to 8th, and the rankings of diets high in trans fats remained at 8th in 1990-2019, as measured by the DALYs (Fig. 6B). However, diets low in vegetables and high in processed meat, showed large declines in rankings (Fig. 6A), and diets low in vegetables declined by 39.5%, and the DALY rate declined by 11.0% (Fig. 6B).