Why are we normally advised to take bland and nourishing food when we are sick

Why are we normally advised to take bland and nourishing food when we are sick? 

Answer: When we are sick, generally it affects on our digestion and we lose appetite. Bland food is low-fibre, non-spicy and easy to digest food. It helps

in digestion and provides necessary nourishment. 

In case of patients suffering from gastrointestinal problems like ulcer, bland diet helps recover from such problems. Bland diet helps in improving the immunity and regeneration of healthy body tissues.

On the other hand oily, spicy and fried food cannot be easily digested by sick patients and this food is not recommended.