The regression of reported BMI by gender and body shape perception gave the most balanced results for both genders : the Kappa and ICC obtained were 0.63 95 % CI = [ 0.50-0 .76 ] and 0.67 , 95 % CI = [ 0.58-0 .74 ] for boys ; 0.65 95 % CI = [ 0.52-0 .78 ] and 0.74 , 95 % CI = [ 0.66-0 .81 ] for girls .