I gained 2.9 pounds from that binge (plus some nachos later in the evening)
The fact is that 3500 surplus calories (over and above what you burn through living and exercise) is needed to make one pound of fat. If you calculate out the calories in your binge - the chances are that it will be a lot less than 2.9 * 3500.
I absolutely had 4 pieces of pizza 6 chicken wings and two diet cokes for dinner today
Calories in one KFC chicken wing from calorie count...
180 calories per wing.
Calories in Pizza Hut Super Supreme per slice - 305 calories
Calories in Dominos ultimate deep dish per slice - 366 calories
Calories in diet coke - negligible - I drank it all through losing weight...
So - we are looking at no more than
4 * 380 for pizza and looking on the high side of calorie options
plus
6 * 200 for chicken wings - again on the high side of calorie options
1520 for pizza plus 1200 for wings = 2720.
This is not enough to gain a pound of fat - even if the rest of the food that you ate in the day takes up your entire calorie allowance for the day which would be a fair bit higher than your standard burn because you exercised.
The surplus weight will be far from all fat.
A lot of food of that type is high in sodium. That causes water retention. Some of the surplus will be water which is retained until you drink enough water to flush it out.
The food and liquid has weight in your stomach until you go to the toilet too...
Some of it will be laid to fat.
The best thing to do is to aim not to do it again too often, drink plenty of water and try to eat food which contains less sodium. Eating less processed food is generally a good idea.
Beating yourself up over such transgressions never gets anyone anywhere...