Hello, I Have Noticed That 2 Hours After Eating An

Hello, I have noticed that 2 hours after eating an evening low carb meal, around 25 grams that my heart rate when sitting is in the normal 65-70 rate but when I get up and start walking around or go get a drink of water the rate is between 100-110. I don't feel anything, no symptons like chest pain, lite headed, dizzy, etc. It just freaks me out. If I sit back down and then maybe 30 minutes to an hour later and get up again it's in the upper 80's to low 90's. I'm a big guy at 335lbs but continuing to lose weight. Does this seem normal? It's not that high during the day when I get up & walk around, just seems always after eating. Thanks, Doug