Early complementary feeding tied to increased childhood adiposity

Introduction of complementary feeding (CF) at <4 months appears to be associated with increased adiposity in mid-childhood and early adolescence, regardless of whether the infants were breastfed or formula-fed, a study has shown.

Using data from the Project Viva* cohort, the researchers prospectively analysed 1,013 children (mid-childhood, mean age 7.9 years; early adolescence, mean age 13.2 years). Of these, 69 percent were breastfed for ≥4 months and 31 percent were formula-fed (never breastfed or stopped breastfeeding at <4 months). The children were categorized according to time of CF introduction: <4 months (19 percent), 4 to <6 months (68 percent), and ≥6 months (14 percent). [Pediatrics 2019;144:e20191320]

At mid-childhood and early adolescence, breastfed children who received CF at <4 months had an increased waist circumference (2.71 and 3.48 cm, respectively), BMI z-score (0.34 and 0.34), and DXA** truncal fat mass (0.53 and 1.72 kg) and whole-body fat percentage (1.76 percent and 2.41 percent) compared with those who started CF at 4 to <6 months.

Introduction of CF at <4 months was also associated with increased BMI z-score, waist circumference, DXA truncal fat mass, sum of skinfolds, and skinfold ratio in formula-fed children (0.43, 3.17 cm, 0.64 kg, 4.85 mm, and 0.08, respectively, in mid-childhood, and 0.47, 4.63 cm, 1.44 kg, 6.22 mm, and 0.13, respectively, in early adolescence) compared with CF introduction at 4 to <6 months.

“[Of note,] CF introduction at ≥6 months also seemed to be associated with other adiposity measures with estimated effect sizes similar to or greater than what we observed for [early] CF introduction at <4 months in formula-fed children,” the researchers noted. “This finding was not initially expected and needs to be interpreted with caution considering the small number of formula-fed participants with CF introduction at ≥6 months.”

The most common complementary foods fed to children at <4 months were infant cereals (15.3 percent), fruits (5.7 percent), and fruit juice (5.6 percent).

In breastfed children, early intake of infant cereals and fruit juice was associated with increased BMI z-score (0.28) and waist circumference (2.24 cm) during mid-childhood, the latter persisting through early adolescence (3.02 cm).

Increases in BMI z-score (0.33) and waist circumference (2.58 cm) in mid-childhood were also observed among formula-fed children who had an early intake of infant cereals, though only an increase in BMI z-score (0.31) was observed through early adolescence.

“Interestingly, the magnitude of the effect for early introduction of CF remained rather large for overall adiposity [from mid-childhood] up to early adolescence, [with stronger associations seen in formula-fed children],” noted the researchers.

Moreover, associations between late CF introduction and higher adiposity were noted in formula-fed children only, they said.

“Our findings, along with those from previous studies, [also] suggest no clear benefit in delaying CF introduction beyond 6 months, which is in line with recommendations from the European guidelines … [However,] more studies are needed with contemporary cohorts recruited after the implementation of the newest guidelines to better understand the effects of CF introduction beyond 6 months,” said the researchers. [J Pediatr Gastroenterol Nutr 2017;64:119-132; Ital J Pediatr 2015;41:36]

“[Overall, our] findings support the [current guideline] recommendations not to introduce CF at <4 months [or at >6 months] in children and suggest that delaying CF introduction could possibly be detrimental for obesity prevention [particularly] in formula-fed children,” said the researchers. [Ital J Pediatr 2015;41:36]

“The child’s feeding environment and behaviours during CF should be further explored and considered for more comprehensive guidance on CF introduction,” they added.

*Project Viva: A Longitudinal Study of Health for the Next Generation

**DXA: Dual-energy radiograph absorptiometry