Was this water weight that I gained?

I lost between 5-6 pounds with a new weight loss strategy then gained back 2-3 pounds in one day and now my weight loss is going down again, I think it might be water weight gain because my sodium intake and liquid intake was very high the day before I gained 2-3 pounds. And I always gain weight when I consume the 2 foods that led to my weight gain that day, one had 650 milligrams of sodium and the other had 270 milligrams of sodium, but I had around 3 servings of it.
Was this water weight that I gained?
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