It also reached number one in 58 countries and received multi-platinum certifications in Australia, Canada, Denmark, Italy, Mexico, New Zealand, Norway, Sweden, Spain, and the United Kingdom, becoming the fourth best-selling song of 2014 with 11 million copies sold worldwide.

[13] The song was produced, engineered, programmed, sound designed, and mixed by Kadish—who also played drums, electric guitar, and bass guitar—at the Carriage House studio in Nolensville, Tennessee.

[6][18] Kelsey McKinney of Vox characterized it as retro-R&B pop,[19] while Slate's Chris Molanphy described its style as "vintage white-girl, Italo-Latin soul".

[9] "All About That Bass" was released as the lead single from Trainor's debut extended play (EP) Title in 2014 and her studio album of the same name the following year.

[34] Epic Records released the song for digital download in several countries on June 30, 2014, as Trainor's debut single,[35][36][37] and serviced it to radio stations in the United States on the following day.

[46] As "All About That Bass" began rising in popularity, Radio Disney's vice president of programming Phil Guerini asked Epic to send it a family-friendly version of the song with lyrics suitable for all audiences.

[26] Jon Caramanica of The New York Times called it a "shimmery" and "cheeky [...] hit" but criticized Trainor's unenthusiastic and drawn-out delivery, and accused her of imitating black music.

[19][21][51] Kris Ex of Complex said Trainor imitated body standards often used to stereotype black women and appropriated colloquialisms that are associated with African-American Vernacular English.

[52] Alexa Camp of Slant Magazine called the song "faux empowerment" and criticized Trainor for encouraging women to rely on men's opinions for validation.

[19] The Independent writer Yomi Adegoke argued the track's substitution of conventional beauty standards with new ones is a poor representation of body positivity, and was insulted by its statement men find only curvy women attractive.

[9][49] Ashley White of Florida Today thought the song did not shame thin women, instead interpreting its lyrical message as "no one—skinny, fat or in between—should have to feel uncomfortable or imperfect in their skin".

[33] Sullivan stated that while the track's palatable nature and retro-inspired "cuteness" contributed to its success, the unwavering body-positive message of its lyrics was its biggest appeal.

[9] Stereogum's Chris DeVille considered criticisms of the lyrics valid but praised the "pleasant swagger" in Trainor's expressionless delivery and its joyful nature, finding it a clever update on its retro influences.

[77] The Recording Industry Association of America (RIAA) certified the song Diamond, which denotes 10 million units based on sales and track-equivalent on-demand streams.

[82] Following its release for digital download, the song peaked at number one and sold 884,000 copies;[83][84] the British Phonographic Industry (BPI) certified it 3× Platinum.

To that end, Robinson suggested using subdued pastel colors, which would popularize the video during summer, and depicting Trainor as an ingénue doing "booty-bumping dance moves and just shaking it up".

[133][134] Entertainment Weekly's Miles Raymer wrote the video's dance sequence and colorful sets were perfectly designed to attain online popularity.

[48] USA Today writer Brian Mansfield described the clip's theme as a fusion of Sir Mix-a-Lot's "Baby Got Back" (1992) and "Beauty School Dropout" from the 1971 musical Grease.

[138] Diana Cook of Cracked.com felt it displayed a double standard, saying there would be much more of a backlash if Taylor Swift created a song about men preferring smaller bodies and mocked an overweight woman eating a cupcake in its video.

Rolling Stone writer Ryan Reed commented the unlikely arrangement maintained the quality of the original version with its "sparse percussion and intimate doo-wop harmonies" supporting her impassioned delivery.

[148] On November 26, Trainor sang a medley of "All About That Bass" and "Lips Are Movin" (2014) on the finale of the nineteenth season of American television series Dancing with the Stars.

[151] On the final episode of The X Factor UK's eleventh series, Trainor performed the song with finalists Andrea Faustini, Fleur East and Ben Haenow.

[153][154][155] Trainor reprised the song on November 22, 2018, while wearing "a glittery jersey and sparkly blue pants" at a Dallas Cowboys and Washington Redskins game, which launched The Salvation Army's 128th annual Red Kettle Campaign.

[158] She reprised the song with Kelly Clarkson on the latter's show on April 29, 2024, to celebrate its 10-year anniversary,[159][160] and two months later at iHeartRadio's Can't Cancel Pride 2024 with the Gay Men's Chorus of Los Angeles and Capital's Summertime Ball 2024.

[163][164] Josh Duboff of Vanity Fair stated "All About That Bass" achieved "pop-cultural touchstone-status" while The New York Times's Joe Coscarelli called it "a cultural phenomenon".

[168][169] Rolling Stone's Steve Knopper wrote; "if we assume the latest sing-about-your-butt trend in pop music has finally reached its, uh, conclusion, the unquestionable winner is Meghan Trainor's 'All About That Bass'".

The video, which depicts NASA interns dancing and includes images of the Johnson Space Center, accrued over one million views within four days and was dubbed "wonderfully a-dork-able" by Lee Moran of the New York Daily News.

In it, Daniel D'Addario attributed the song's popularity among parodists to its hook's emphasis on the words "bass" and "treble", which are easy to rhyme, and Trainor's impassioned delivery on it.

[181] The Roots covered "All About That Bass" on The Tonight Show Starring Jimmy Fallon on August 20, 2014; Chris Payne of Billboard called the performance "angelic".

[187] Jamaican-American singer Anita Antoinette covered the song on the seventh season of the American talent television series The Voice, receiving praise by the show's judges Pharrell Williams and Adam Levine.