. FOSSTEVIA (FOS+STEVIA) is a natural and healthy substitute of sugar full of goodness of prebiotics and dietary fiber brought to you through natural Stevia plant extract and FOS (Fructooligosaccharides). 2. FOS occurs naturally in nature. It is a prebiotic dietary fiber found in several fruits and vegetables and produced through natural and safe processes. 3. STEVIA is a plant native to south America.The natural sweetener derived from the sweet leaf plant has no calorie, no fat & no carbs and is used as a sweet herb or sugar substitute from decades. Usage-1. Fosstevia can be used as a natural sugar substitute in all hot or cold beverages