I would probably try and track it, myself...
Just so I could use it as a "point of reference" if for no other reason. Just so I could maybe compare this day to the next "office party" and see if I do better the next time?
That said... if it is really a jumble and impossible to guesstimate, just chalk it up to "a bad day" and start again tomorrow.
Goal 1 - break 200 (46 pounds lost)**DONE**
Goal 2 - leave obesity behind (BMI 29.9, at 185#) **DONE**
Goal 3 - BMI = Normal (154# or less)
| current weight: 172.5