I often get questions and hear comments from people trying to lose weight. I hear things like, "Why did I eat 2 bowls of ice cream and lose 2 pounds and then not eat all day and gain 5?!"
I've already written about weight loss here and here. This won't be a rehash of that. I just wanted to show you a sample of 'normal' weight fluctuation. The picture above is from daily (or nearly daily) readings at similar times each night on the same scale. I didn't include the numbers because they don't matter, but the readings swing around inside about a 5 pound bandwidth.
I'm not trying to gain or lose weight so there isn't a trend one way or the other. If you were trying to lose, you would want the right side of the chart to start trending down over time (think in weeks, not days), but you'd still expect to see daily bouncing.
That's totally normal and expected. Your body weight will swing for a variety of factors - the most obvious being water. Ate something salty yesterday? Your body will likely retain more water today. That doesn't mean you're "gaining weight" so don't freak out. Just build a plan, stay with it, and keep things moving the right direction.
Enjoy your day!