Does diet quality or nutrient quantity contribute more to health?

Western diet is a leading risk factor for chronic illness and death (1). A recent study in the journal Lancet addressed key questions pertaining to the health-related effects of nutrition as assessed through the dietary components (2). The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 Diet Collaborators evaluated 15 dietary factors for their effects on mortality and disability from cardiovascular diseases, diabetes, and cancer across 195 countries (2). Adding to their previous findings (3), the GBD study made a number of key observations. First, the consumption of healthy diet was suboptimal worldwide (i.e., low intake of nuts and seeds, milk, and whole grains), whereas the consumption of unhealthy diet (i.e., sugary beverages, salt, and processed and red meat) was more common. Second, the examined dietary factors were potentially responsible for a high disease burden, including 11 million (95% uncertainty interval, 10-12) deaths and 255 million (95% uncertainty interval, 234-274) disability-adjusted life-years (DALYs; 22% of all deaths and 15% of all DALYs in adults aged 25 years or older). Third, three factors, including high intake of sodium, low intake of whole grains, and low intake of fruit, accounted for more than 50% of diet-related deaths and two-thirds of diet-related DALYs. These findings were consistent across different regions of the world.