Cosmetic use of at least one glycoside chosen from glycosides having the following general formula: Sacc-(CH 2) i -X-R in which: - Sacc represents a monosaccharide or a polysaccharide comprising up to 20 sugar units, in the form of pyranose and/or furanose and L and/or D serie, said mono- or poly-saccharide being possibly substituted by a necessarily free hydroxy group, and/or possibly one or several amine function(s) that are possibly protected; - i is 0 or 1; - X is a heteroatom, or is chosen from the group consisting of the -C(R a)=N-O-, -C(=O)-, -C(=S)-, -C(-SR a) and -C(R b)(R c)- groups, R a representing H or a linear or branched (C 1 -C 6)alkyl group, R b and R c, are identical or different, representing H or a group chosen from the group consisting of hydroxy, alkoxy(C 1 -C 6), alkoxy(C 1 -C 6)amino, alkoxy(C 1 -C 6)ammonium, alkoxy(C 1 -C 6)-diamino, amino, (C 1 -C 6)alkylamino, di((C 1 -C 6)alkyl)amino, hydroxy(C 1 -C 6)alkylamino, di(hydroxy(C 1 -C 6)alkyl)amino, and (hetero)arylamino groups; - R represents a (C 1 -C 10)alkyl, linear or branched, said alkyl group being possibly substituted by at least one substituent chosen from the group consisting of OR a, -C OH and -C OR" 2, R" 2 being a linear or branched (C 1 -C 4)alkyl group; or R represents a (C 1 -C 4)alkyl(C 6 -C 10)aryl group, said aryl group being possibly substituted by at least one substituent OR e, R e representing H or a linear or branched (C 1 -C 6)alkyl group; the Sacc-(CH 2) i -X bond representing a bond of a C-anomeric nature, which can be α or β, as well as the salts thereof, the solvates thereof such as hydrates and the optical and geometric isomers thereof, in order to increase the diameter of the hair fiber. - Sacc represents a monosaccharide or a polysaccharide comprising up to 20 sugar units, in the form of pyranose and/or furanose and L and/or D serie, said mono- or poly-saccharide being possibly substituted by a necessarily free hydroxy group, and/or possibly one or several amine function(s) that are possibly protected; - i is 0 or 1; - X is a heteroatom, or is chosen from the group consisting of the -C(R a)=N-O-, -C(=O)-, -C(=S)-, -C(-SR a) and -C(R b)(R c)- groups, R a representing H or a linear or branched (C 1 -C 6)alkyl group, R b and R c, are identical or different, representing H or a group chosen from the group consisting of hydroxy, alkoxy(C 1 -C 6), alkoxy(C 1 -C 6)amino, alkoxy(C 1 -C 6)ammonium, alkoxy(C 1 -C 6)-diamino, amino, (C 1 -C 6)alkylamino, di((C 1 -C 6)alkyl)amino, hydroxy(C 1 -C 6)alkylamino, di(hydroxy(C 1 -C 6)alkyl)amino, and (hetero)arylamino groups; - R represents a (C 1 -C 10)alkyl, linear or branched, said alkyl group being possibly substituted by at least one substituent chosen from the group consisting of OR a, -C OH and -C OR" 2, R" 2 being a linear or branched (C 1 -C 4)alkyl group; or R represents a (C 1 -C 4)alkyl(C 6 -C 10)aryl group, said aryl group being possibly substituted by at least one substituent OR e, R e representing H or a linear or branched (C 1 -C 6)alkyl group; the Sacc-(CH 2) i -X bond representing a bond of a C-anomeric nature, which can be α or β, as well as the salts thereof, the solvates thereof such as hydrates and the optical and geometric isomers thereof, in order to increase the diameter of the hair fiber.