The body-positive movement has encouraged people, especially women, to see beauty in all shapes and sizes, and it's reminded us that body ideals are culturally constructed and not based on science.

For bodybuilders and fitness enthusiasts, changing body composition often reflects hard work and discipline—but knowing body composition is useful for anyone, and for more than just bragging rights.

Smart scales track changes in your muscle mass, body fat percentage and other health metrics — but how do smart scales work, and how accurate are they? When you purchase through links on our site, we ...