Could it be water gain? The reason I ask, I am reading up on the Flat Belly Diet put out by Prevention and they talk about raw vs cooked veggies. Cooked is better b/c takes up less room in GI tract. Same calories in a cup of carrots, but retention wise 1/2 cup of raw equals 1 cup cooked. Also brocolli and cauliflower and some other raw veggies they list as belly bloating foods. Just a thought. 3 pounds sounds a lot like water to me.