As someone who went from skinny to strong herself, Kayla Itsines has been an inspiration to women all over the world in the past few years.
Her Bikini Body Guides have blown up Instagram, helping not only her own account rack up over 5 million followers, but her fans gain fans too.
Despite guiding 10 million people to weightloss success, Kayla has also showed women that a number on the scale isn't everything.
Using her 12-week guides and app - which contain LISS, HIIT and her own gym-inspired workouts - #BBG girls can't help but share their transformation pictures with the world via social media.
Muscle may weigh more than fat but when it means looking toned and healthy, these girls know that fitness is key.
Here are some of the cases that prove whether you gain weight, stay the same or lose only a few pounds, you can still completely change the shape of your body.