Why would my weight go up 4 pounds after eating out and staying within my calorie limit?

I just don't get it.  My weight went up 4 pounds after eating out twice.  I kept within my calorie limit even.  Unless I'm totally inaccurate on the amount of food I ate, I just don't get it.

This always happens to me.  When I eat at home, I lose weight. When I eat out, my weight always goes up.

If you are able to view the nutritional content of the food you ate out, please glance at the Sodium, I'm sure you will find why your weight went up so suddenly.

Normal Sodium intake is 1500-2000mg

your not gonna gain 4 pounds of fat is your staying within your limit. remember, water weighs 8 pounds per gallon. If you have 4 glasses of water at dinner your gaining 1 pound. this is why it is important to not weigh yourself every day. your weight WILL fluctuate because of the weight of the food youve digested. If you are holding a sandwich in your hand and step on the scale its going to say the same thing if you were to eat the sandwich and step on the scale. Like i said dont worry about it, as long as your within your limit your fine.

I'm with Nocturne- I'm guessing it is the sodium content.... This always happens to me on Mondays after a weekend of "almost free eating." Then by Tuesday I'm back down again...

Happens to me, too--restaurant food is loaded with salt, and sometimes MSG as well.  I tend to stop losing weight for a while after eating out, until I've lost the water I retained because of it.