The Complementary Roles for Plant-Source and Animal-Source Foods in Sustainable Healthy Diets

There are approximately 100 countries with food-based dietary guidelines throughout the world, each of which aims to encompass the cultural, geographical, and health considerations unique to their country of origin. Common themes throughout these guides emphasize diverse and balanced intake of food groups from both plant- and animal-sources. With the globally recognized need to shift to more sustainable food systems, several countries and international food and health organizations have begun to incorporate sustainability recommendations into their dietary guidance. These sustainability recommendations are often based on food source (i.e., eat more plant-source and fewer animal-source foods), yet food source may not be the only useful or informative comparator for assessing healthy and sustainable diets. The purpose of this narrative review is to examine the roles of plant-source foods and animal-source foods in the context of sustainable healthy diets—with an emphasis on the contributions of the most commonly recommended food groups from global food-based dietary guidelines (i.e., fruits, vegetables, and dairy foods). Overall, plant and animal agriculture have complementary and symbiotic roles in healthy and sustainable food systems, and these abilities are largely dependent on various contextual factors (e.g., geography, production practices, processing methods, consumption patterns)—not just on whether the food originated from the plant or animal kingdom.