It would be so easy to convert the majority of vegans back into omnivores. All you’d need to do is take away the modern food distribution system servicing grocery stores, supermarkets, food buying clubs, and restaurants. Most vegans do not
This link will take you to the Raw Till 4 website. This way of living promotes eating raw fruits and vegetables and ZERO animal products. While it is not primarily a weight loss diet, it will definitely make you drop weight very quickly.