Great question! Make sure you are clear with the interviewer that you follow a healthy lifestyle by choice, and it's something you enjoy doing. Give examples of ways you eat healthy, and how you avoid making grave mistakes at McDonalds. Here's an example answer: 'A healthy lifestyle is very important to me, as I want to be active and healthy when I am in my fifties. I frequently visit a few healthy eating blogs, research articles, watch youtube videos and follow Pinterest to discover new recipes. I recently saw a new avocado salad recipe on Pinterest, and I made it yesterday. It was amazing!' The key to this question is demonstrating to the interviewer how serious you are with health. Interviewer is trying to avoid phony candidates, that want a job where they can goof off at.