On the other hand, the contribution small levels of exercise (such as getting up from your desk and walking at a normal pace, even climbing a few flights of stairs a couple of times per day) to calorie consumption is likely to be almost nothing - a few dozens of kcal over the course of a day at best. I know that there have been studies for example of the additional kcal consumption from a standing desk compared to a normal desk, and the result is almost non-existent, less than 10 kcal over the course of a workday.