New here... is possible 4 lbs gain overnight?

I am on a diet the last month and half and I have lost ( I thought) 3-4 lbs so far and I am (was) very happy because I am not very good in dieting...!  Long story sort, I went at a company event last night and I ate and drunk some white wine very late at night.  This morning as always I stepped on the scale and was expecting a weight gain since I ate so late etc. and I almost started crying when I saw that I GAINED 4 lbs overnight.  Is that possible??  I didn't even eat more than 3500 calories all day yesterday.  Is anything I could do? I guess start from the beginning?  I'm clueless at this point.

Body weight fluctuates daily, so it is best to weigh yourself only once a week at the same time of day each time.  Body weight can be influenced by (for ladies) time of month due to fluid retention, or by something as simple as not having been to the... erm..... toilet!  Dont beat yourself up, and dont get back on the scales until next week.  Good luck.

Absolutely lol. If you eat more sodium i think, your body retains water. And water is heavy! Just drink a lot of water today. It will flush out your system. And dont worry!! If youre keeping up your diet, you'll lose the extra water weight within a day or so.

Its obviously temporary.

Unless you ate 14000 calories over your MAINTENENCE, (2000?) (which is very hard to do in one day) then you could impossibly gain 4 lbs of fat in one day. It just doesnt work like that.

Its water and the weight of the food you ate, chillax.

it's like how i weigh myself in the morning and i'm 117 and once i eat if i weigh myself again i'll be 118. no, i haven't eaten 3500 calories so there's no way i could've actually gained a lb, but it's just the weight of all the food you ate. i'm sure you didn't eat 5500 calories that night, and that would only be for one lb. don't worry, it's temporary!

I'm with the others - it's only temporary.

The exact same thing happens to me after a day when I eat quite a bit more than I'm used to, and I gain around 4 lbs on the scale.

But then I get back to my regular eating habits, and it all comes off. I've found that it takes about 4 days for all of the water weight/waste to come out again. :)

Thank you all for your replies. I'm feeling much better but again I weighted myself this morning and only 2 were off.  I guess like nakuranu said I have to wait four days to see my old new weight.  But at least after your replies I really stopped beating my self up by miday and enjoyed the rest.  Thank you!!