The human body is a complex thing, and it’s hard to know exactly why you might look skinny in the morning. But there are some common explanations that might help.

One possible reason for the phenomenon is the effect of water retention. As you go through your day, your body uses up water to do things like keep your organs functioning and sweat out heat. If you don’t drink enough water, your body won’t be able to replace this lost fluid, so it will begin to retain what it has left — which means more water in your tissues. As a result, you’ll look thinner after eating breakfast or drinking coffee because the extra water is being stored in places like your tissue and not on your skin.

You may also look skinnier if you wake up dehydrated. This is especially true if you’re a heavy sleeper who doesn’t get much sleep at night (or simply doesn’t wake up until late morning). In this scenario, if you don’t drink enough water during the night, or even just wake up late enough that breakfast isn’t an option (or both), your body will have been without water for hours by the time you start moving around again in the morning — which means that it will retain every drop of fluid it can get its hands.

Last modified: November 27, 2022