"3 Spoons of Suga" is an uptempo pop song, with elements of dance-pop. Nick Levine of Digital Spy described it as a "Nancy Sinatra-style pop strut". He also suggested that the song "doesn't sound like anything the Sugababes have recorded before", and went on to name it a "kissing cousin" to the group's 2008 single, "Girls". Levine noted that "Boys and Girls" by Pixie Lott has a "passing resemblance" to "3 Spoons of Suga". Matt O'Leary of Virgin Media noted the incorporation of a guitar in the "beat-led dancefloor" track. An editor from "The Scotsman" suggested the line "He don't get stressed cos he's blessed by the cut of his jeans" was reminiscent of songs released by British girl group Girls Aloud.