Denying favourite food is cruelty?

Hi I am a 31 year old Hindu male married to a Hindu 27 year old girl. I love my wife very much and she also loves me very much. She was born in a vegetarian family and I am a non - vegetarian. She does not eat any non veg food after marriage. I am a person with free thoughts and respect her choice. I have never forced or even suggested her to have chicken, mutton, fish, beef or pork. I let her have her type of food and love her for her choice of food and do not also expect her to cook non veg for me, my father or friends. I am myself a very good cook and can cook my non veg food. She does not have a problem with this either. Problem is with my mother in law who suggests that I should quit eating non veg. When she visits my place I cannot cook non veg. I am fine with this even. It is Ok if I do not have non veg for 15 - 20 days when my mother in law is around, for the love and respect I have for my wife. But, my mother in law whenever she comes to my place suggests that non veg food is bad and I must quit it. She says it makes a person violent. She along with my father in law threw away some spices / masalas used to prepare chicken secretly, from our kitchen, which I discovered a few days later. I let them use my kitchen as their own and never tried to force my liking on them. I just need to know if it is good for them to force their liking on me. When I respect someones liking I expect them to respect my beliefs and likings. I don't like being told constantly that the non veg food I eat is bad and useless. My mother in law once told me that my father should quit non veg as he is a senior citizen and a widower. How can I ask my father to give up his liking for fish / meat /chicken? My mother in law once told that we would bear "disabled children" if I continued to have non veg food. This is I feel derogatory. I want to know that if this is "cruelty"? I do not want a divorce from my wife, I love her intensely. I feel any one who comes in between us I will fight and it is my right to protect the well being of my household. Please advise.