Impact of Breastfeeding on Adolescent Body Composition

Overview of the Study

A recent prospective longitudinal study investigated the influence of breastfeeding on body composition in adolescents. This research is particularly relevant in Brazil, where obesity rates are increasing across all demographics. While body mass index (BMI) is often used to assess obesity, it fails to differentiate between fat mass and fat-free mass.

Early Life Factors Influencing Adult Health

Numerous studies indicate that early life factors, such as weight gain and breastfeeding duration, significantly impact health outcomes in adulthood. The study published in BMC Nutrition focused on these aspects by analyzing data from adolescents born in 1993 in Pelotas, Brazil. The final sample included 1,438 births, with assessments conducted at 6 months, 12 months, 48 months, and 18 years of age.

Methodology

Researchers conducted in-home interviews with mothers to gather information on breastfeeding practices, including the duration of breastfeeding and the introduction of other milk products and solid foods. The hypothesis was that longer and exclusive breastfeeding would correlate with higher fat-free mass indexes in adolescents.

Body Composition Assessment

In addition to BMI, the study utilized other metrics to evaluate weight status and body composition. The fat-free mass index (FFMI) assesses the body mass derived from muscle, organs, bones, water, and connective tissues, while the fat mass index (FMI) measures body mass from fat.

Nutritional Variables and Body Composition Results

The average FFMI for males in the study was 19.0 kg/m², and the average FMI was 4.0 kg/m². For females, the average FMI and FFMI were 8.0 kg/m² and 15.5 kg/m², respectively. The findings revealed that FFMI was associated with various socioeconomic and genetic factors. Notably, FMI was higher among males from higher-income households, and both FMI and FFMI were linked to the mother’s pre-pregnancy BMI.

Influence of Breastfeeding on Body Composition

The study found that FFMI in males was associated with breastfeeding duration, while females who were breastfed had a higher FFMI compared to those who were not breastfed. Additionally, females who began consuming semisolid and solid foods at four to five months exhibited higher FFMI and FMI. However, the timing of introducing other milk ingredients did not correlate with FMI in females.

Conclusions and Implications

The findings suggest that breastfeeding significantly affects body composition in later life for both genders. While the introduction of semisolid and solid foods correlated with body composition changes in females only, the study uniquely focused on adolescents rather than children, providing valuable insights into early nutritional impacts on adult health. A limitation noted was the lack of examination of specific semisolid and solid foods consumed, but the study contributes to understanding the role of early nutritional exposure on long-term health.

References

Orlandi, S.P., González-Chica, D.A., Buffarini, R., Gonzalez, M.C., Menezes, A.M.B., Barros, F.C., and Assunção, M.C.F. (2017). Breastfeeding and complementary feeding associated with body composition in 18–19 years old adolescents in the 1993 Pelotas Birth Cohort. BMC Nutrition, 3(84). https://doi.org/10.1186/s40795-017-0201-z.