Though some people do lose weight upon becoming vegan (which makes sense because you're eating fewer calorie-dense foods) and though vegans do have a lower body mass index than non-vegetarians, weight loss is not automatic for everyone. Rather than promise that "if you go vegan, you will lose weight," it's much more accurate to say "people who switch from an animal-based diet to a plant-based diet tend to lose weight effortlessly because plants are much less calorie-dense than animal flesh and secretions." For those for whom weight loss is a goal, it's simply a numbers game: decreasing energy intake and increasing calorie output – and remember – calories are just units of energy. Today we talk about reducing calories.