Our thoughts and our thinking plays a very important role in our life . If we have a kind and loving heart we will sure eat a diet where there is no killing of animals involve . There are thousands on the planet who eat animals for their food but if the doctor advices them ,that ,it’s going to cause more problems in their system then they will sure eat a diet which is based on plants . What’s the harm in having a heart which is kind and loving cause love and kindness adds to our good karmas. People leave Non vegetarian food when advised by doctor is also good but the thought process changes because of their selfish motive.