A double blind, controlled, randomized, single site clinical trial of 2 parallel groups (Low protein formula =LoF and High protein formula =HiF) with a breastfeeding group (BF) as reference from birth to 1 year of age and a follow up period from 1 year to 5 years of age.

The primary objective of this clinical trial is to show that infants taking (from birth) either a formula with a low protein content (LoF) or breast milk will have an IGF-1 level, at 4 months, 25% lower to the IGF-1 measured in infants that received a high protein content formula (HiF).

The secondary objectives are: The hormonal profile; the Fat mass (FM) gain and the Lean mass (LM); the metabolomics and aminogramm during the first year of life.

Subjects are included in the study for a duration of 5 years. From birth to 4 months they are exclusively fed BF or FF. From 4 months of age they can start diversification, but they maintain the starter formulas until 12 months (the BF group will receive LoF). Subjects are then followed up until 5 years of age.

Inclusion Criteria:

. Healthy newborn infant

• Full term infant (= 37 weeks gestation; = 42 weeks gestation)
• Birth weight = 2500 g and < 4200 g
• Singleton birth
• Infant is = 7 days of age at the time of enrollment
• For the BF group: The infant's mother has elected to exclusively breastfeed her baby, from enrollment to 4 months of age For the FF groups: The infant's mother has elected to exclusively formula feed her baby, from enrollment to 4 months of age
• Having obtained his/her or his/her legal representative's consent

Exclusion Criteria:

• Newborn whose mother's BMI was normal (<20 or = 25) at start of pregnancy

  • Newborn whose mother had developed gestational diabetes during pregnancy
  • Newborn whose mother has diabetes of type-1 or type-2
  • Newborn whose mother smoked > 5 cigarettes / day during pregnancy
  • Newborn whose mother had a drug dependence during pregnancy
  • Newborn whose mother has a chronic infectious disease
  • Newborn whose parents / caregivers cannot be expected to comply with treatment
  • Newborn currently participating in another clinical trial