Since last 2 weeks my baby has lost around 400 grms of weight. Having running nose and cough

Question

Accepted Answer

This can occur due to either allergy or infection and some times due to weather changes and temperature variations around the child.
For cold you can give drops maxtra / wikoryl AF 0.5 ml to the child 2-3 times per day. 
try to prevent temperature variations around the child and give nasal saline drops every three hourly for nasal blockage and simple cough and cold. Indirect steam will also help.

Go for home remedies like Tulsi Ginger diluted with water combination and turmeric with milk at least 2 times per day.(honey can be added after 1 year age)
Give warm water to drink 
If no improvement in 2 or 3 days then meet your doctor 
For fever and pain give paracetamol.

it is important to continue the regular diet of the child and the diet during cough and cold will not change much. but it is always advisable to give easily digestible food and do not force the child for food and if the child is taking around f60% to 70% of the diet then also it's fine.
during cough and cold it is important to give plenty of fluids and water to the child which will help in recovery and also citrus fruits are advisable