Thanks for posting your query at HealthCareMagic. Let me mention that for growth you primarily need two food components. The energy that we spend, comes from carbohydrates which come from cereal based food like rice, breads etc. On the other hand, our body is built from proteins which form the basic structure of the body including the muscles and other tissues. So proteins are essential. Animal proteins contain all the basic amino acids that are required by us. Animal proteins are called first class proteins. Plants proteins are not of that quality and do not contain all the essential amino acids. So animal proteins, be it eggs, fish or milk need to be consumed alongwith plant proteins like pulses, soyabeans, carrots, spinach etc. for proper growth even if you wish to avoid meat. Protein intake is a must and cannot be avoided.

I hope that answers your query. Feel free to communicate back in case of further queries if any.