While both regular and vegan mayonnaise are high in fat, vegan mayo tends to be lower in saturated fat and higher in monounsaturated fats. However, to replace egg yolks, vegan mayos can contain several thickeners, modified starch and/or gums to give it a similar texture. Plus, it often contains sugar, which is why it should still be consumed in moderation. You can read more about it in this article comparing mayos.