Is One’s Heart Rate Related To Their Eating And Drinking Habits?

Hi Dr. Rynne. I am a 39 year old female, non smoker, non drinker, no drugs. I am currently in the process of losing weight (nothing drastic, modified South Beach, lots of water, (I drink 2 cups of coffee in the morning and nothing but water the rest of the day, and I walk 30 minutes a night). In seven weeks I ve gone from 287 to 271. Lately, my heart rate has been high(ish). My blood pressure is normal 118/79 (last time it was checked) but my heart rate was 108, and after 15 minutes of resting quietly, it retested at 126. I need it to be 100 or lower, because I donate plasma to make extra money (Long story short, my daughter had her right occiptal lobe removed in Feb to get rid of her PXA tumor and I am paying the bill) Could it be something in my new eating / drinking habits?