Breastfeeding as the Norm for Infant Feeding

The growth patterns of breastfed and formula-fed infants are different. For example,

  • Healthy breastfed infants typically put on weight more slowly than formula-fed infants in the first year of life.1-2
  • Formula-fed infants typically gain weight more quickly after about 3 months of age.
  • Differences in weight patterns continue even after complimentary foods are introduced.1

Linear growth generally follows a similar pattern for both breastfed and formula-fed infants.

 Image of a couple with a newborn
WHO Growth Standards

The WHO growth standard charts consider the effect of infant feeding on growth by using breastfeeding as the norm.

When the WHO growth curves were created, the differences in growth patterns of breastfed and formula-fed infants were considered.3

  • A healthy breastfed infant is the standard against which all other infants are compared.
  • All infants in the WHO sample were breastfed at least until aged 12 months and predominantly breastfed for at least 4 months.
  • Complementary foods were introduced at the mean age of 5.4 months.

The breastfed infant is the reference or normative model against which alternative feeding methods are measured with regard to growth, healthy development, and all other short-term and long-term outcomes.4

This is consistent with U.S. dietary reference intakes, in which norms for infant intakes of most nutrients are determined on the basis of the composition of human milk and the average volume of human milk intake.5

CDC Growth Reference

CDC growth reference charts were developed to represent all infants in the United States. Feeding criteria were not identified.

The CDC growth reference charts are based on primarily formula-fed infants.

  • Only about 50% of U.S. infants measured to create the CDC growth reference charts were ever breastfed.
  • By age 3 months, only 33% of U.S. infants were breastfed.

In the United States most infants start to breastfeed.6

As a result, the CDC growth charts may not adequately reflect the current growth patterns of infants in the United States. They also do not reflect the growth pattern typically seen in breastfed infants.


1Dewey KG. Growth characteristics of breast-fed compared to formula-fed infants. Biol Neonate. 1998;74(2):94-105.

2Dewey KG. Growth patterns of breastfed infants and the current status of growth charts for infants. J Hum Lact. 1998;14(2):89-92.

3de Onis M, Garza C, Vicotra CG, Onyango AW, Frongillo EA, Martines J; for the WHO Multicentre Growth Reference Study Group. The WHO Multicentre Growth Reference Study: planning, study design, and methodology. Food Nutr Bull. 2004;25(suppl 1):S15-S26.

4American Academy of Pediatrics. Policy Statement. Breastfeeding and the use of human milk. Pediatrics. 2012:129(3):e827-e841.

5Otten JJ, Hellwig JP, Meyers LD, eds. Dietary Reference Intake: The Essential Guide to Nutrient Requirements. Washington, DC: The National Academies Press; 2006.

6Centers for Disease Control and Prevention. Breastfeeding Report Cards. Accessed September 2, 2015.