Safeguarding diet quality in a changing climate: a scoping review

Background Climate change is increasingly recognized as a driver of declines in crop nutrient content; however, the evidence remains fragmented. This scoping review maps and synthesizes current knowledge on climate change and the nutrient quality of vegetables, legumes, and grains. Methods A systematic online search of peer-reviewed experimental, meta-analytical, and modeling studies published between 1950 and 2024 was conducted, using standardized extraction methods to ensure consistency and quality. Results Experimental studies ( n = 132) and meta-analyses ( n = 9) showed average increases in total carbohydrates (+11%; +17%), simple sugars (+12%; +11%), antioxidants (+14%; +43%), vitamin C (+12%; +6%), and vitamin E (+5%), alongside significant declines in dietary fiber (−13%), folate (−30%) and essential minerals (−3%; −8%), respectively. Modeling studies ( n = 2) projected declines in global nutrient availability of up to −4% for protein and −3% for zinc and iron. Discussion Staple foods that feed billions are losing key nutrients, driving a shift toward energy-dense, nutrient-poor diets that heighten hidden hunger and chronic disease risks. Warranting the need for nutrition-sensitive climate adaptation strategies.