New Job - Sitting for 5 1/2 hours a day - not good!

I've been on MFP in the past. I reached my goal and I have been feeling GREAT! The weight has stayed off for about 8 months. My eating and exercising are pretty consistent, BUT, I got a new job in February which requires me to sit at a desk for 5 1/2 hours a day. I have to answer the phones so I can't wander off to walk or stretch or get any type of activity. I am allowed a 15 minute break at which time I sit down to eat a lean protein and complex carb because I work noon-5;30, it is important that I eat something. Then back to my desk to sit some more. Don't get me wrong, I'm a hard core workout and nutrition nut! I am in boot camp 3 days a week, kettle bell 1 day a week and I run 2 days a week. I had a food alergy test last August and found out that I can not tolerate dairy, eggs and chocolate. I eliminated both them for 6 months. I'm allowed to have them again and see how my body reacts. So far so good, but only in moderation. My problem....since I started this job, I am up 4 pounds. Do you have any suggestions for me?? I haven't worked outside of the home in 4 years. But I was always cleaning, mowing, shoveling, scrubbing, washing, etc. Some days I never even sat down until after I washed the supper dishes.