A fatty hydroxy acid and / or a fatty oxo acid for use in the prophylaxis or treatment of at least one condition selected from the group consisting of obesity, diabetes, hyperlipidemia and fatty liver, wherein the fatty hydroxy acid is at least one selected compound between the group consisting of 10-hydroxy-cis-12-octadecenoic acid, 10-hydroxy-cis-12, cis-15-octadecadienoic acid, 10-hydroxy-cis-6, cis-12-octadecadienoic acid, 10-hydroxy acid -cis-6, cis-12, cis-15-octadecatrienoic, 10,12-dihydroxyoctadecanoic acid, 10-hydroxy-cis-15-octadecenoic acid, 10-hydroxy-cis-6-octadecenoic acid, 10-hydroxy-cis acid -6, cis-15-octadecadienoic, 10-hydroxy-trans-11-octadecenoic acid, 10-hydroxy-trans-11, cis-15-octadecadienoic acid, 10-hydroxy-cis-6, trans-11-octadecadienoic acid, and 10-hydroxy-cis-6, trans-11, cis-15-octadecatrienoic acid, and the fatty oxo acid is at least one compound selected from the group consisting of 10-oxo-ci acid. s-12-octadecenoic acid, 10-oxo-cis-12, cis-15-octadecadienoic acid, 10-oxo-cis-6, cis-12-octadecadienoic acid, 10-oxo-cis-6, cis-12, cis acid -15- octadecatrienoic, 10-oxo-octadecanoic acid, 10-oxo-cis-6-octadecenoic acid, 10-oxo-cis-15-octadecenoic acid, 10-oxo-cis-6, cis-15-octadecadienoic acid, acid 12-oxo-octadecanoic, 10-oxo-trans-11-octadecenoic acid, 10-oxo-cis-6, trans-11-octadecadienoic acid, 10-oxo-trans-11, cis-15-octadecadienoic acid, 10- oxo-cis-6, trans-11, cis-15-octadecatrienoic, and 12-oxo-cis-9-octadecenoic acidUn hidroxiácido graso y/o un oxoácido graso para su uso en la profilaxis o el tratamiento de al menos una condición seleccionada entre el grupo que consiste en obesidad, diabetes, hiperlipidemia e hígado graso, en donde el hidroxiácido graso es al menos un compuesto seleccionado entre el grupo consistente en ácido 10-hidroxi-cis-12- octadecenoico, ácido 10-hidroxi-cis-12, cis-15-octadecadienoico, ácido 10-hidroxi-cis-6, cis-12-octadecadienoico, ácido 10-hidroxi-cis-6, cis-12, cis-15-octadecatrienoico, ácido 10,12-d
