A nutritional system comprising: • at least one male gender specific synthetic nutritional composition for an infant up to 1 month of age wherein, the total protein content is adapted based on that found in human milk produced for an infant of the same gender and age and wherein said total protein content is 0.7 to 2.3g /100mL, preferably wherein the gender specific synthetic nutritional composition is selected from the groups consisting of: infant formula, and a composition for infants that is intended to be added to or diluted with human milk fortifier, and • at least one female gender specific synthetic nutritional composition for an infant up to 1 month of age wherein, the total protein content is adapted based on that found in human milk produced for an infant of the same gender and age and wherein said total protein content is 0.2 to 2.0g /100mL, preferably wherein the gender specific synthetic nutritional composition is selected from the groups consisting of: infant formula, and a composition for infants that is intended to be added to or diluted with human milk fortifier, wherein said gender specific synthetic nutritional compositions are for infants of the same age, and wherein the total protein content in said male gender specific nutritional composition is higher than that of said female gender specific synthetic nutritional composition and wherein said nutritional system further comprises gender specific synthetic nutritional compositions for infants of more than 1 month of age wherein, the total protein content of said gender specific synthetic nutritional compositions does not differ by gender for infants of the same age and/or wherein said nutritional system further comprises gender neutral synthetic nutritional compositions for infants of more than 1 month of age. • at least one male gender specific synthetic nutritional composition for an infant up to 1 month of age wherein, the total protein content is adapted based on that found in human milk produced for an infant of the same gender and age and wherein said total protein content is 0.7 to 2.3g /100mL, preferably wherein the gender specific synthetic nutritional composition is selected from the groups consisting of: infant formula, and a composition for infants that is intended to be added to or diluted with human milk fortifier, and • at least one female gender specific synthetic nutritional composition for an infant up to 1 month of age wherein, the total protein content is adapted based on that found in human milk produced for an infant of the same gender and age and wherein said total protein content is 0.2 to 2.0g /100mL, preferably wherein the gender specific synthetic nutritional composition is selected from the groups consisting of: infant formula, and a composition for infants that is intended to be added to or diluted with human milk fortifier, wherein said gender specific synthetic nutritional compositions are for infants of the same age, and wherein the total protein content in said male gender specific nutritional composition is higher than that of said female gender specific synthetic nutritional composition and wherein said nutritional system further comprises gender specific synthetic nutritional compositions for infants of more than 1 month of age wherein, the total protein content of said gender specific synthetic nutritional compositions does not differ by gender for infants of the same age and/or wherein said nutritional system further comprises gender neutral synthetic nutritional compositions for infants of more than 1 month of age.