Abs-olutely! Summer's Sexiest Six-Packs

From Nick Jonas to Jennifer Aniston to Shakira, see which stars are impressing with their taut tummies

SHAKIRA

Less than a year after welcoming son Milan, The Voice judge bared her rock-hard midsection for the September cover of Self magazine and revealed that she began getting back in shape when her son was 2 months old. "Two minutes of ab work isn't enough," she said, going on to describe her diet as eight small meals a day, between 200-250 calories each, and consisting of lots of fiber, protein, calcium, iron and fish oil.