The scale is fickle: we lose weight when we pee or when we do a sweaty workout. We gain weight when we eat or drink or put on a sweater. But how much does that kind of fluctuation really impact the numbers we see? I weighed myself fifteen times in one day to find out. 140.3 pounds at 9:16am: I step on the scale for the first time. I’ve just woken up. I’m wearing light pajamas. 138.9 pounds at 9:19am: After going to the bathroom. Apparently my bladder can hold at least 1.4 pounds of urine. Well, that’s a new thing I learned. 141.6 pounds at 9:23am: Fully dressed, in jeans and shoes. This is how I’ll weigh myself for the rest of the day, because I’m not getting naked every time I want to step on the scale. 143.2 pounds at 9:24am: Oops, forgot my hoodie. That’s 4.3 pounds of clothing in total. 145.4 pounds at 10:35am: After breakfast, which apparently weighed 2.2 pounds including beverages. 144.4 pounds at 11:45am: After pooping. That’s a one pound poop. 147.0 pounds at 2:23pm: After late lunch/early dinner. Full bladder. 145.8 pounds at 2:28pm: Peed again, 1.2 pounds. 145.1 pounds at 5:58pm: Didn’t do anything special in the last few hours. Lost over half a pound! 144.3 pounds at 6:57pm: Ditto. Another half pound gone. Losing weight is easy! 142.4 pounds at 7:04pm: In workout clothes and hoodie. I’m back to my pre-breakfast weight. Now it’s time for a Nike Training Club workout (the one they call “Lifted by Lunges”). 142.3 pounds at 7:45pm: After a 30-minute workout. I drank most of a pint of water (a pint weighs a pound) and apparently sweated the same amount. 140.1 pounds at 8:15pm: Naked, after shower, damp hair. This is the least I’ll weigh all evening. 142.9 pounds at 11:07pm: One last weigh-in wearing regular clothes. 142.4 pounds at 11:09pm: In my pajamas. We typically lose a few pounds while we sleep. I was down to 139.3 the next morning, within a pound of my initial weigh-in. I think of myself as a 140-pound person, but my highest weight was 147. My lowest was 138.9. Note that most of the daytime weights included about four pounds of clothes—so they aren’t my “true” weight, but they’re what I would see if I stepped on a scale during the day. I know you’ve seen that scale at the gym, or maybe you have one in your bathroom that sort of taunts you as you sit on the toilet looking at it. Source I knew I’d see fluctuations, but I was surprised at how big they were. We’re often told to weigh ourselves first thing in the morning, after going to the bathroom but before eating breakfast. That corresponds to my lowest weight in the experiment, and it makes sense that it would also be the most consistent. Even this number will change from day to day, of course, depending on things like exactly how hydrated you are.
