Can eating too healthily make you ill?

 Summary:

She wanted to have a good look so she became a vegetarian at 15. Soon she became a vegan. She gives up anything that came from animals and doesn't eat salt, sugar and no processed. She kept losing wirght and got ill with frequent bouts of flu. She has no enough energy most days. So that we should not have a too healthily diet. It won't make you feel good. It just make you ill.