I saw someone on Twitter this morning lamenting about how hard it is to only weigh herself once a week. I quickly fired off a response, then jumped into Excel to PROVE myself. It’s a Saturday morning and I drank a bit more wine than I should have last night, and so, having found something WRONG on the internet…
Well, that’s just a cause to throw myself at!
Your body has about +/- 2 liters of water that it will naturally regulate as it needs to, from day to day.
That means your weight may fluctuate +/- 4 pounds essentially *at random*.
I could talk you through some scenarios, but to make it easier, let’s look at a graph.
I randomly generated these data around the idea that a person can fluctuate 2 lb, up or down from “resting” weight, due to just hydration variation (all the hydration states are considered within normal).
Blue is the “real” weight; this is a steady loss of 1.4 lb over the course of a week, which is a healthy and realistic goal. In possibility 1, the green line, you see the person has a spike, drop, slight rise, slight drop, then back up and ends the week well. If this person (let’s go with “he,” for argument’s sake) weighed himself on days 1 and 6, he would see about a 1.5 lb drop over the course of the week. Not bad. The orange scenario (possibility 3) is about the same, though he would have seen a change from 200.5 lb to around 197 lb and would think he’s outperforming.
However, look at the red and yellow examples. Despite the fact that he is losing weight quickly (1.4 lb a week is great at that weight!) measuring on days 1 and 7 would make him think he had gained substantial weight, and he would likely feel discouraged.
So it’s important to weigh yourself every day, at the same time, at the same “state.” For me, I wake up, walk to the restroom, use the toilet, and then stand on the scale. It’s just a habit. After I’ve been up and had coffee, or breakfast, or gone to the gym, my weight could be all over the place, and I don’t do those other things EVERY SINGLE DAY. There’s some variation. So just right when I wake up works really well, as it’s the most consistent.
Here’s an example of my actual weight data in my first few months of the ketogenic diet. You’ll notice some gaps (I think I was doing some traveling) but I was pretty consistent about measuring every day.
I have and love a Withings scale, so the data goes straight to my Apple Health app, which then feeds that data to my 5x5 workout app, and so in theory I can compare my weight to strength ratio. This is really helpful, and keeps me on track.
Just remember: weigh yourself every day, at the same time, if you want to see the most accurate numbers. I would recommend doing this right when you get up in the morning, but find a time that works for you. Consistency is key.