Daily Smart Fact #32: Why You’re Fattest at Night and Skinniest in the Morning

Takeaway: You lose more than a pound every night from breathing.  That’s because you breathe in oxygen (O2) and breathe out carbon dioxide (CO2 – two oxygen atoms plus a carbon atom), “so there’s an extra carbon atom leaving in every round trip.”

I like weighing myself.  Call it my own personal body experiment, but I enjoy seeing the fluctuations of my weight throughout the day – in the morning, after I eat, before/after I go to the restroom, right at night.  It might sound obsessive, but I’m not trying to lose weight – it’s just fascinating to observe the fundamentals of input/output on your own body. Eat a POUND of cheese?  Yeah, you’ve just gained an immediate pound.  Drink 24 oz of water?  Yeah, you just gained 24 oz. on that scale.

Anyway, I stumbled upon a neat article that my friend (hi Li!) posted on Facebook and found it intriguing: Every Night You Lose More Than a Pound While You’re Asleep (For the Oddest Reason).  Basically, this guy records himself over a couple of days weighing himself at night and then again in the morning, wearing the same clothes.  He interviews people and eats hamburgers and goes to the bathroom, fun stuff.  Not the most rigorous scientific experiment.  But his finding at the end is that, just breathing at night, thousands of breaths over a typical 8-hour sleep, results in us losing about a pound or more just from the extra carbon that gets expelled.

Pretty neat, huh? I always assumed it was water loss – just our bodies sweating and evaporating water.  Well…

As communities go, someone commented on the author’s post and noted that we lose more weight at night due to water loss – which I can totally buy. I wake up thirsty (the hypochondriac in me thought I had diabetes when I was younger).  According to this commenter, our body moistens the surface of our lungs so that when we exhale, our warmed-up-exhaled-air is warmer than we inhaled and much more humid.  Each gram of dry air we exhale also “carries with it 0.0272 grams of water vapor.” Add that up thousands of times and yeah, we lose carbons plus a lot more water just by breathing.

This got me wondering, “are there breathing exercises that help me lose weight?” Of course, a quick google search results in a lot of YES to this question.  Who knew all the great benefits of just breathing? I feel so bad for…worms. Check it out.