What we eat is rapidly becoming an issue of global concern. With food shortages, the rise in chronic disease, and global warming, the impact of our dietary choices seems more relevant today than ever. Globally, a transition is taking place toward greater consumption of foods of animal origin, in lieu of plant-based diets. With this transition comes intensification of animal agriculture that in turn is associated with the emergence of zoonotic infectious diseases, environmental degradation, and the epidemics of chronic disease and obesity. Health professionals should be aware of these trends and consider them as they promote healthier and more environmentally-sustainable diets.