An apparatus (100) for measuring body fat mass and degree of obesity of a person (P) is provided. According to one aspect, the apparatus comprises a second bar (102) optionally configured to be placed on a horizontal surface, and a first bar (101) configured to be movable along and being perpendicular to said second bar (102) and an optional control unit (111). A first connecting means (105) connects said first bar (101) to said second bar (102). A light emitting device (104) is connected to said first sliding member (103) and is configured to emit light in a direction perpendicular to the plane defined by the first and second bar (101, 102). According to another aspect, the apparatus comprises a hanging bar (129) configured to be placed in front of said person (P), a supporting bar (128) configured to provide support for the hanging bar (129), a second sliding member (133) being slidingly connected to said hanging bar (129), at least one light emitting device (104) configured to emit a sheet of light (114) directed toward the body of said person (P) whereby at least one line (L4) is projected onto the body of said person (P), at least one camera (134) configured to detect line (L4), wherein at least one of either said at least one light emitting device (104) or said at least one camera (134) is connected to said second sliding member (133). A system and a method thereof is also provided.
