Fitness blogger Tiffany Brien reminded the world of that fact by posting to Instagram.
She took two photos of her stomach -- one as soon as she woke up, and one 12 hours later just before she went to bed.
The difference is striking.
"No I'm not 6 months pregnant. It's just my food baby," Tiffany wrote. "We are not all what we seem on social media. I thought I would share a bad day with you to show you nobody is 'perfect' and it is ok to have an off day where your body just decides to not play ball," she added.
Brien is one of many stars who have taken to the internet to prove that life on social media is never as it seems.
A photo posted by Tiffany Brien (@tiffanybrien) on
"Don't worry girls, it happens to the best of us, all part and parcel of being a female!" she added.
Brien thinks a "delightful cocktail of lack of sleep, stress, hormones and food intolerances" was the cause of her bloat, so take note.
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FILE - In this Sept. 21, 2013 photo, Ke$ha arrives at the iHeartRadio Music Festival, at the MGM Grand Garden Arena in Las Vegas. Ke$ha has checked into rehab to treat an eating disorder. The "Tik Tok" singer says in a statement provided by her spokesman Friday, Jan. 3, 2014 that she'll be unavailable for the next 30 days while she seeks treatment for an undisclosed eating disorder. (Photo by Eric Jamison/Invision/AP Images, File)
WASHINGTON, DC- MAY 18: Sarah Feliciano prepares for her morning shower at the Wanda Alston House on May 18, 2011, in Washington, DC. She said, 'This is what hormones do to my body,' as she rubs her hips and display signs of breasts. Sarah Feliciano was living at DC's National Airport when an airport employee told her about the Wanda Alston House, a transitional home specifically for homeless Gay Lesbian Bisexual Transgender (GLBT) youth, ages 16 to 24, and it's the only one of its kind in DC. According to a 2005 article in the Washington Post, Wanda Alston was a feminist and gay rights activist who had served since 2001 as D.C. Mayor Anthony A. Williams's liaison to the gay, lesbian, bisexual and transgender community when she was killed in 2005 in her Northeast Washington home. Police said a crack-addled neighbor stabbed her eight times, took her car and used her credit cards to raise cash for more drugs. (Photo by Jahi Chikwendiu/The Washington Post via Getty Images)
LONDON - FEBRUARY 29: (UK TABLOID NEWSPAPERS OUT) Shilpa Shetty participates in a 'BodyTalk' self esteem workshop with pupils from the Seebright Primary School as part of Real Beauty Day, on February 29, 2008 in Hackney, London. She joins hundreds of Dove staff around the world hosting workshops to celebrate the 'leap day' of the year.February 29, 2008 in London, England.(Photo by Gareth Davies/Getty Images)
LONDON - FEBRUARY 29: (UK TABLOID NEWSPAPERS OUT) Shilpa Shetty participating in a 'BodyTalk' self esteem workshop with pupils from the Seebright Primary School,Hackney, London as part of Real Beauty Day. She joins hundreds of Dove staff around the world hosting workshops to celebrate the 'leap day' of the year.February 29, 2008 in London, England.(Photo by Gareth Davies/Getty Images)