A compound of formula: wherein X is selected from the group consisting of a single bond, an oxygen atom and a -NH- group; when X is O, R 1 is selected from the group consisting of a) C 1-8 -alkyl, optionally substituted by one C 1-8 alkoxy group, b) C 6-10 -aryl-C 1-4 alkyl and c) C 5-10 heteroaryl-C 1-4 alkyl wherein the C 5-10 heteroaryl rest comprises 1 to 3 heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur, when X is a single bond or a -NH- group, R 1 is selected from the group consisting of d) phenyl optionally substituted by 1 to 3 substituents selected from the group consisting of OH, NR 5 R 6, CN, CF 3, C 1-6 linear or branched alkyl; C 1-6 linear or branched alkoxy and halogen atoms; e) naphthyl optionally substituted by 1 to 3 substituents selected from the group consisting of OH, NR 5 R 6, CN, CF 3, C 1-6 linear or branched alkyl, C 1-6 linear or branched alkoxy and halogen atoms; f) C 5-10 heterocyclyl-C 0-2 alkyl wherein the heterocyclyl rest is saturated or unsaturated and comprises 1 to 3 heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur and is optionally substituted by 1 to 3 substituents selected from the group consisting of OH, NR 5 R 6, CN, CF 3, C 1-6 linear or branched alkyl and halogen atoms; g) C 1-6 linear or branched alkyl, optionally substituted by one C 1-8 alkoxy group and h) C 3-6 cycloalkyl-C 0-2 alkyl optionally substituted by 1 to 3 substituents selected from the group consisting of OH, NH 2, CN, CF 3, C 1-6 linear or branched alkyl and halogen atoms; R 2 is selected from the group consisting of i) C 1-8 -alkyl optionally substituted with 1, 2 or 3 fluor atoms, j) C 1-8 -alkoxy-O-C 1-8 -alkyl and k) C 3-6 cycloalkyl-C 0-2 alkyl wherein the cycloalkyl ring is optionally substituted with 1, 2 or 3 fluor atoms; R 3 is selected from the group consisting of 1) C 1-8 -alkyl and m) benzyl optionally substituted by 1 to 3 substituents selected from the group consisting of C 1-4 -alkyl, MeO, CN and halogen atoms; R 4 is selected from the group consisting of n) C 1-8 -alkyl, o) C 3-6 cycloalkyl-C 0-2 alkyl optionally substituted by C 1-4 -alkyl and p) C 1-8 -alkoxy; and R 5 and R 6 are independently selected from the group consisting of hydrogen atoms and C 1-6 linear or branched alkyl groups; or a pharmaceutically acceptable salt thereof for use in the treatment and/or prevention of an obesity-related condition selected from the group consisting of obesity, lipid storage disease and hyperlipemia. X is selected from the group consisting of a single bond, an oxygen atom and a -NH- group; when X is O, R 1 is selected from the group consisting of a) C 1-8 -alkyl, optionally substituted by one C 1-8 alkoxy group, b) C 6-10 -aryl-C 1-4 alkyl and c) C 5-10 heteroaryl-C 1-4 alkyl wherein the C 5-10 heteroaryl rest comprises 1 to 3 heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur, when X is a single bond or a -NH- group, R 1 is selected from the group consisting of d) phenyl optionally substituted by 1 to 3 substituents selected from the group consisting of OH, NR 5 R 6, CN, CF 3, C 1-6 linear or branched alkyl; C 1-6 linear or branched alkoxy and halogen atoms; e) naphthyl optionally substituted by 1 to 3 substituents selected from the group consisting of OH, NR 5 R 6, CN, CF 3, C 1-6 linear or branched alkyl, C 1-6 linear or branched alkoxy and halogen atoms; f) C 5-10 heterocyclyl-C 0-2 alkyl wherein the heterocyclyl rest is saturated or unsaturated and comprises 1 to 3 heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur and is optionally substituted by 1 to 3 substituents selected from the group consisting of OH, NR 5 R 6, CN, CF 3, C 1-6 linear or branched alkyl and halogen atoms; g) C 1-6 linear or branched alkyl, optionally substituted by one C 1-8 alkoxy group and h) C 3-6 cycloalkyl-C 0-2 alkyl optionally substituted by 1 to 3 substituents selected from the group consisting of OH, NH 2, CN, CF 3, C 1-6 linear or branched alkyl and halogen atoms; R 2 is selected from the group consisting of i) C 1-8 -alkyl optionally substituted with 1, 2 or 3 fluor atoms, j) C 1-8 -alkoxy-O-C 1-8 -alkyl and k) C 3-6 cycloalkyl-C 0-2 alkyl wherein the cycloalkyl ring is optionally substituted with 1, 2 or 3 fluor atoms; R 3 is selected from the group consisting of 1) C 1-8 -alkyl and m) benzyl optionally substituted by 1 to 3 substituents selected from the group consisting of C 1-4 -alkyl, MeO, CN and halogen atoms; R 4 is selected from the group consisting of n) C 1-8 -alkyl, o) C 3-6 cycloalkyl-C 0-2 alkyl optionally substituted by C 1-4 -alkyl and p) C 1-8 -alkoxy; and R 5 and R 6 are independently selected from the group consisting of hydrogen atoms and C 1-6 linear or branched alkyl groups;