Why eating onion and garlic is prohibited and not potatoes during fasting?

Why eating onion and garlic is prohibited and not potatoes during fasting?

Dr. K K Aggarwal, President Heart Care Foundation of India and Group Editor in Chief MEDtalks, will discuss why potatoes are allowed during fasting in this video. He explains that anything underground shouldn’t be eaten raw, it should be cooked. During fasting, if anyone wants to eat potato can cook and eat it.