Globally, one in five deaths are associated with poor diet
People in almost every region of the world could benefit from rebalancing their diets to eat optimal amounts of various foods and nutrients, according to the Global Burden of Disease study tracking trends in consumption of 15 dietary factors from 1990 to 2017 in 195 countries, published in The Lancet.
The study estimates that one in five deaths globally -- equivalent to 11 million deaths -- are associated with poor diet, and diet contributes to a range of chronic diseases in people around the world. In 2017, more deaths were caused by diets with too low amounts of foods such as whole grains, fruit, nuts and seeds than by diets with high levels of foods like trans fats, sugary drinks, and high levels of red and processed meats.
The authors say that their findings highlight the urgent need for coordinated global efforts to improve diet, through collaboration with various sections of the food system and policies that drive balanced diets.
"This study affirms what many have thought for several years -- that poor diet is responsible for more deaths than any other risk factor in the world," says study author Dr Christopher Murray, Director of the Institute for Health Metrics and Evaluation, University of Washington, USA. "While sodium, sugar, and fat have been the focus of policy debates over the past two decades, our assessment suggests the leading dietary risk factors are high intake of sodium, or low intake of healthy foods, such as whole grains, fruit, nuts and seeds, and vegetables. The paper also highlights the need for comprehensive interventions to promote the production, distribution, and consumption of healthy foods across all nations."
Impact of diet on non-communicable diseases and mortality
The study evaluated the consumption of major foods and nutrients across 195 countries and quantified the impact of poor diets on death and disease from non-communicable diseases (specifically cancers, cardiovascular diseases, and diabetes). It tracked trends between 1990 and 2017.
Previously, population level assessment of the health effects of suboptimal diet has not been possible because of the complexities of characterising dietary consumption across different nations. The new study combines and analyses data from epidemiological studies -- in the absence of long-term randomised trials which are not always feasible in nutrition -- to identify associations between dietary factors and non-communicable diseases.
The study looked at 15 dietary elements -- diets low in fruits, vegetables, legumes, whole grains, nuts and seeds, milk, fibre, calcium, seafood omega-3 fatty acids, polyunsaturated fats, and diets high in red meat, processed meat, sugar-sweetened beverages, trans fatty acids, and sodium. The authors note that there were varying levels of data available for each dietary factor, which increases the statistical uncertainty of these estimates -- for example, while data on how many people ate most dietary factors was available for almost all countries (95%), data for the sodium estimates was only available for around one in four countries.
Overall in 2017, an estimated 11 million deaths were attributable to poor diet. Diets high in sodium, low in whole grains, and low in fruit together accounted for more than half of all diet-related deaths globally in 2017.
The causes of these deaths included 10 million deaths from cardiovascular disease, 913,000 cancer deaths, and almost 339,000 deaths from type 2 diabetes. Deaths related to diet have increased from 8 million in 1990, largely due to increases in the population and population aging.