You can't believe everything you see on Instagram — especially when it comes to weight loss "transformation" photos. It's all too easy to fake major weight loss or muscle gain by tweaking posture, clothing, camera angle, and lighting.

Don't believe it? Fitness blogger Madalin Giorgetta has the video proof to convince you for good, Cosmopolitan reports.

Last week, Giorgetta posted this side-by-side comparison to show how posture adjustment (and a little muscle flexing) can radically change the look of her body:

"I love seeing these photos on my feed as it reminds me that we all have our best angles that we choose to share," she wrote in the caption. "The girls you see on Instagram don't walk around with one leg bent and one hip popped and flexed abs the whole time! I don't look like the right version in real life because who the hell stands like that in real life?"

But the difference between the two photos was so dramatic that some commenters accused Giorgetta of using Photoshop to alter her body. In response, she posted this video, showing the "transformation" in real time:

"It's called the human body and it moves in and out because I'm not a statue," she captioned the video. (Amen to that.)

Giorgetta's posts are an excellent reminder that before-and-afters can be deceiving — and that no one's body should look the same at all hours of the day. So what if your stomach bulges out when you sit down? That's what it's supposed to do.

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