The present invention generally relates to the field of nutrition. In particular the present invention relates to infant nutrition in the post natal period and in early life, more particular during the age period of 6-36 months or during a part thereof. One embodiment of the present invention is a kit of diet compositions for children during the age period of 6-36 months or during a part thereof, wherein the macronutrient content of the compositions is gradually changing in the form of a straight line from a composition that comprises about 40-50% energy from fat and about 40-49% energy from carbohydrates for children at the age of 6 months to a composition that comprises about 30-35% energy from fat and about 50-55% energy from carbohydrates for children at the age of 36 months, and its use to prevent obesity later in life.