In 2017, the World Health Organization (WHO) reported that mental illness was the leading cause of disability worldwide. They estimated that over 300 million people suffer from depression and over 260 million people suffer from anxiety. These estimates reflect a substantial increase in the number of people living with mental disorders over the past two decades... In parallel with increments in mental disorders, vegetarianism and veganism have become more popular and prevalent worldwide.. As a result, the question of whether meat consumption or avoidance is associated with better mental health has become a controversial issue in public health and nutrition science... Briefly, we found that the majority of studies showed that meat abstainers (vegetarians and vegans) had substantially higher rates or risk of depression, anxiety, and/or self-harm. Additionally, these groups were more likely to be prescribed medication for mental-health issues.