The world's population is burgeoning having increased from four billion in 1975 to 7.4 billion at the beginning of 2016. Thus, we need more food and this places more pressure on the environment. Coincident with this change, rates of obesity and of adverse mental health conditions are increasing in most developed countries and also in some developing countries thus burdening health systems. Furthermore, in the time that the world's population has doubled, the consumption of meat has tripled. Large population studies associate high meat consumption with deleterious health and reduced longevity so much so that the World Health Organization has labelled meat a carcinogen. Modern meat production depends on intensive animal production and the feeding of crops to animals, commonly known as “factory farming” or, more formally, “Industrial Farm Animal Production” (IFAP). This industry produces such a high proportion of the animals we eat that any reduction in meat eating will likely see less IFAP. The dominance of IFAP makes it a key contributor to climate change, with emissions estimated at 7.1 gigatonnes CO2-equivalents per annum, or 14.5% of human-induced greenhouse gas emissions. Added to this, the intensive production of animals raises many questions concerning their welfare. In this paper I argue that a largely vegetarian diet makes environmental sense while also offering health benefits and improved animal welfare. The latter occurs by farming fewer animals and by caring for them better. I focus on the health benefits because this is the crux of the issue; if people ate less meat – moved towards a vegetarian diet, then we would be healthier and would also mitigate the environmental and animal welfare problems associated with IFAP. Education is the key. If people understand the origins of their food and the benefits to gain by eating a largely plant-based diet – one where plants are the staples, then there is some hope of tackling a system that has enormous economic and political power. Currently, education fails; only 5% of Australians eat the recommended helpings of fruit and vegetables and do the recommended amount of exercise. The best change we could make in terms of health, environment and welfare would be to refrain from the offerings of the fast-food industry. These food outlets depend on IFAP and have been widely criticised for marketing unhealthy products. The small amounts of meat eaten in a semi-vegetarian existence would come from sustainable animal production where welfare is paramount.