I'm always baffled when my weight jumps up like that. For me it's wine. If I have a night out with friends and sharing a bottle or two, my weight can fluctuate by 5 pounds over night. I'm sure there are things along with it that I'm not realizing, but in the end I'm sure that it's water weight to be that drastic. However, I find getting those pounds off are much harder than putting them on overnight. That's what's frustrating. That's why I always get frustrated with myself for putting myself in the position to gain those pounds. But I'm constantly also trying to remind myself that I can't shut myself off from life and that I need to adjust my new eating habits to my life outside of the house....
Anyway, I digress...
I agree with others. It's most likely the sodium and that it's not good to eat a whole bag of those at a time also because of the calories. I'm not so much into cheetos as I am into cheese puffs. They're full of air and processed cheese flavoring, but so addictive. So now I don't even look at them in the grocery store. I like to pretend they don't exist.